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1.
J Biotechnol ; 379: 53-64, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38070779

RESUMO

The baculovirus-insect cell expression system allows addition of O-fucose to EGF-like domains of glycoproteins, following the action of the protein O-fucosyltransferase 1 named POFUT1. In this study, recombinant Spodoptera frugiperda POFUT1 from baculovirus-infected Sf9 cells was compared to recombinant Mus musculus POFUT1 produced by CHO cells. Contrary to recombinant murine POFUT1 carrying two hybrid and/or complex type N-glycans, Spodoptera frugiperda POFUT1 exhibited paucimannose N-glycans, at least on its highly evolutionary conserved across Metazoa NRT site. The abilities of both recombinant enzymes to add in vitro O -fucose to EGF-like domains of three different recombinant mammalian glycoproteins were then explored. In vitro POFUT1-mediated O-fucosylation experiments, followed by click chemistry and blot analyses, showed that Spodoptera frugiperda POFUT1 was able to add O-fucose to mouse NOTCH1 EGF-like 26 and WIF1 EGF-like 3 domains, similarly to the murine counterpart. As proved by mass spectrometry, full-length human WNT Inhibitor Factor 1 expressed by Sf9 cells was also modified with O-fucose. However, Spodoptera frugiperda POFUT1 was unable to modify the single EGF-like domain of mouse PAMR1 with O-fucose, contrary to murine POFUT1. Absence of orthologous proteins such as PAMR1 in insects may explain the enzyme's difficulty in adding O-fucose to a domain that it never encounters naturally.


Assuntos
Fucosiltransferases , Proteínas Recombinantes , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Spodoptera/enzimologia , Spodoptera/genética , Spodoptera/metabolismo , Fucosiltransferases/química , Fucosiltransferases/genética , Fucosiltransferases/metabolismo , Humanos , Animais , Camundongos , Células CHO , Cricetulus , Células Sf9 , Glicosilação , Sequência Consenso , Fucose/metabolismo , Domínios Proteicos
2.
Animals (Basel) ; 13(12)2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37370531

RESUMO

Genetic diversity and phylogenetic relationships within the Arabian show horse populations are of particular interest to breeders worldwide. Using the complete mitochondrial DNA D-loop sequence (916 pb), this study aimed (i) to understand the genetic relationship between three populations, the Desert-Bred (DB), a subset of the Kingdom of Saudi Arabia (KSA), United Arab Emirates (UAE) and Bahrain (BAH), the Straight Egyptian (EG) and the Polish bloodline (PL), and (ii) to assess the accuracy of the traditional strain classification system based on maternal lines, as stated by the Bedouin culture. To that end, we collected 211 hair samples from stud farms renowned for breeding Arabian show horses from Nejd KSA, Bahrain, Egypt, Qatar, Morocco, UAE, and Poland. The phylogenetic and network analyses of the whole mitochondrial DNA D-loop sequence highlighted a great genetic diversity among the Arabian horse populations, in which about 75% of variance was assigned to populations and 25% to strains. The discriminant analysis of principal components illustrated a relative distinction between those populations. A clear subdivision between traditional strains was found in PL, in contrast to the situation of DB and EG populations. However, several Polish horse individuals could not be traced back to the Bedouin tribes by historical documentation and were shown to differ genetically from other studied Bedouin strains, hence motivating extended investigations.

3.
Animals (Basel) ; 12(20)2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36290124

RESUMO

(1) Background: It has been recognized that the origin of fat-tailed sheep occurred within coarse wool breeds and that this character was introgressed several times into thin-tailed populations. However, no study has investigated this idea for Egyptian breeds using mtDNA analyses. (2) Methods: Using new sequences of the control region, we constructed a database of 467 sequences representing 37 breeds including fat- and thin-tailed ones with 80 Egyptian individuals belonging to six local breeds (Barki, Fallahi, Ossimi, Rahmani, Saidi, Sohagi). The phylogenetic tree obtained with the maximum likelihood method was submitted to the Newick Extra program to count the direct and indirect links between the individuals of each breed. (3) Results: Several Egyptian breeds were strongly connected to "primitive" thin-tailed breeds from Europe, indicating a clear genetic background of the "thin tail" breed type that supports the view of archeologists. In several cases, we suspected Western Asian breeds to be involved in the introgression of the fat tail character. In contrast, the Ossimi breed showed a high affinity to a fat-tailed breed of Western Asia, suggesting a direct migration and no thin tail ancestors. The Saidi is unique as our analyses revealed its strong connection with thin-tailed Sudanese breeds.

4.
Glycobiology ; 31(1): 55-68, 2021 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-32518939

RESUMO

Epidermal growth factor-like domains (EGF-LDs) of membrane and secreted proteins can be modified by N-glycans and/or potentially elongated O-linked monosaccharides such as O-glucose (O-Glc) found at two positions (O-Glc 1 and O-Glc2), O-fucose (O-Fuc) and O-N-acetylglucosamine (O-GlcNAc). The presence of three O-linked sugars within the same EGF-LD, such as in EGF-LD 20 of NOTCH1, has rarely been evidenced. We searched in KEGG GENES database to list mouse and human proteins with an EGF-LD sequence including one, two, three or four potential O-glycosylation consensus sites. Among the 129 murine retrieved proteins, most had predicted O-fucosylation and/or O-GlcNAcylation sites. Around 68% of EGF-LDs were subjected to only one O-linked sugar modification and near 5% to three modifications. Among these latter, we focused on the peptidase domain-containing protein associated with muscle regeneration 1 (PAMR1), having only one EGF-LD. To test the ability of this domain to be glycosylated, a correctly folded EGF-LD was produced in Escherichia coli periplasm, purified and subjected to in vitro incubations with the recombinant O-glycosyltransferases POGLUT1, POFUT1 and EOGT, adding O-Glc1, O-Fuc and O-GlcNAc, respectively. Using click chemistry and mass spectrometry, isolated PAMR1 EGF-LD was demonstrated to be modified by the three O-linked sugars. Their presence was individually confirmed on EGF-LD of full-length mouse recombinant PAMR1, with at least some molecules modified by both O-Glc1 and O-Fuc. Overall, these results are consistent with the presence of a triple O-glycosylated EGF-LD in mouse PAMR1.


Assuntos
Acetilglucosamina/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Fucose/metabolismo , Glucose/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Serina Proteases/metabolismo , Acetilglucosamina/química , Animais , Bases de Dados de Proteínas , Fator de Crescimento Epidérmico/química , Fator de Crescimento Epidérmico/isolamento & purificação , Fucose/química , Glucose/química , Humanos , Camundongos , N-Acetilglucosaminiltransferases/química , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Serina Proteases/química
5.
Biomolecules ; 10(9)2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32872229

RESUMO

The Wnt Inhibitory Factor 1 (Wif1), known to inhibit Wnt signaling pathways, is composed of a WIF domain and five EGF-like domains (EGF-LDs) involved in protein interactions. Despite the presence of a potential O-fucosylation site in its EGF-LDs III and V, the O-fucose sites occupancy has never been demonstrated for WIF1. In this study, a phylogenetic analysis on the distribution, conservation and evolution of Wif1 proteins was performed, as well as biochemical approaches focusing on O-fucosylation sites occupancy of recombinant mouse WIF1. In the monophyletic group of gnathostomes, we showed that the consensus sequence for O-fucose modification by Pofut1 is highly conserved in Wif1 EGF-LD III while it was more divergent in EGF-LD V. Using click chemistry and mass spectrometry, we demonstrated that mouse WIF1 was only modified with a non-extended O-fucose on its EGF-LD III. In addition, a decreased amount of mouse WIF1 in the secretome of CHO cells was observed when the O-fucosylation site in EGF-LD III was mutated. Based on sequence comparison and automated protein modeling, we suggest that the absence of O-fucose on EGF-LD V of WIF1 in mouse and probably in most gnathostomes, could be related to EGF-LD V inability to interact with POFUT1.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sequência Consenso , Fator de Crescimento Epidérmico/química , Evolução Molecular , Fucose/metabolismo , Animais , Fator de Crescimento Epidérmico/metabolismo , Fucosiltransferases/metabolismo , Camundongos , Modelos Moleculares , Filogenia , Domínios Proteicos , Proteínas Recombinantes/metabolismo
6.
Sci Rep ; 10(1): 10225, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576960

RESUMO

The arrival of Neolithic culture in North Africa, especially domestic animals has been essentially documented from archaeological records. As the data relative to sheep are scarce, we studied the genetic relationship between Moroccan sheep breeds and Mediterranean ones using the sequencing of 628 bp of the mitochondrial DNA control region in 193 Moroccan individuals, belonging to six breeds, and 652 sequences from other breeds in Europe and Middle East. Through Network analysis and an original phylogenetically derived method, the connection proportions of each Moroccan breed to foreign ones were estimated, highlighting the strong links between Moroccan and Iberian breeds. The first founders of Moroccan sheep population were issued at 79% from Iberia and 21% from a territory between Middle East and Africa. Their calculated expansion times were respectively 7,100 and 8,600 years B.P. This suggests that Neolithization was introduced by a double influence, from Iberia and from another route, maybe Oriental or Sub-Saharan. The consequence of the environmental changes encountered by founders from Iberia was tested using different neutrality tests. There are significant selection signatures at the level of Moroccan and European breeds settled in elevated altitudes, and an erosion of nucleotide diversity in Moroccan breeds living in arid areas.


Assuntos
DNA Mitocondrial/genética , Variação Genética , Genética Populacional , Haplótipos , Ovinos/genética , Animais , Cruzamento , DNA Mitocondrial/análise , Evolução Molecular , Região do Mediterrâneo , Filogenia
7.
Int J Mol Sci ; 20(18)2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31500188

RESUMO

Past work has shown that the protein O-fucosyltransferase 1 (POFUT1) is involved in mammal myogenic differentiation program. Pofut1 knockdown (Po -) in murine C2C12 cells leads to numerous elongated and thin myotubes, suggesting significant defects in secondary fusion. Among the few pathways involved in this process, NFATc2/IL-4 is described as the major one. To unravel the impact of POFUT1 on secondary fusion, we used wild-type (WT) C2C12 and Po - cell lines to follow Myf6, Nfatc2, Il-4 and Il-4rα expressions during a 120 h myogenic differentiation time course. Secreted IL-4 was quantified by ELISA. IL-4Rα expression and its labeling on myogenic cell types were investigated by Western blot and immunofluorescence, respectively. Phenotypic observations of cells treated with IL-4Rα blocking antibody were performed. In Po -, we found a decrease in nuclei number per myotube and a downexpression of Myf6. The observed downregulation of Nfatc2 is correlated to a diminution of secreted IL-4 and to the low level of IL-4Rα for reserve cells. Neutralization of IL-4Rα on WT C2C12 promotes myonuclear accretion defects, similarly to those identified in Po -. Thus, POFUT1 could be a new controller of myotube growth during myogenesis, especially through NFATc2/IL-4 signaling pathway.


Assuntos
Fucosiltransferases/genética , Regulação da Expressão Gênica , Interleucina-4/metabolismo , Desenvolvimento Muscular/genética , Fibras Musculares Esqueléticas/metabolismo , Fatores de Transcrição NFATC/metabolismo , Transdução de Sinais , Animais , Diferenciação Celular/genética , Linhagem Celular , Técnicas de Silenciamento de Genes , Camundongos , Fatores de Transcrição NFATC/genética , Receptores Notch/metabolismo
9.
Cancers (Basel) ; 10(11)2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30380753

RESUMO

BACKGROUND: While protein O-fucosyltransferase 1 (POFUT1) overexpression has been recently proposed as a potential biomarker for different cancer types, no study was carried out on POFUT1 implication in colorectal cancer (CRC). METHODS: Data from 626 tumors and 51 non-tumor adjacent tissues available in FireBrowse had been used in this study. Statistical analyses on POFUT1 expression and gene copy number, NOTCH receptors (main targets of POFUT1 enzymatic activity) expression and association of POFUT1 and NOTCH1 expressions with clinical parameters were investigated. Data were completed by POFUT1 histological labeling on six tumor tissues from patients with CRC. RESULTS: We found that POFUT1 is overexpressed from the stage I (p < 0.001) and 76.02% of tumors have a 20q11.21 amplification, associated in 90.13% of cases with a POFUT1 overexpression, compared to non-tumor adjacent tissues. The POFUT1 copy number in tumors is mainly between 2 and 3. POFUT1 is positively correlated with NOTCH1 (rs = 0.34, p < 0.001), NOTCH3 (rs = 0.087, p = 0.0297), and NOTCH4 (rs = 0.097, p = 0.0148) expressions, while negatively correlated with NOTCH2 expression (rs = -0.098, p = 0.0142). POFUT1 overexpression is markedly associated with rectal location, non-mucinous adenocarcinoma and cancer stages IV and M1. NOTCH1 overexpression is only associated with rectal location and non-mucinous adenocarcinoma. CONCLUSION: We conclude that POFUT1 is overexpressed in CRC from stage I, and its high expression is associated with metastatic process, probably through NOTCH pathway activation. Then, POFUT1 could represent a potential novel biomarker for CRC diagnosis.

10.
DNA Cell Biol ; 37(4): 359-372, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29634421

RESUMO

The protein O-glucosyltransferase 1 (Poglut1) links O-glucose to epidermal growth factor-like repeats harboring the C1XSX(P/A)C2 consensus sequence. Poglut1 is a ubiquitous endoplasmic reticulum-resident protein largely found in metazoans, but only about 50 proteins possess this consensus sequence. Among them, Notch receptors have multiple O-glucosylation sites and their activation depends on this status. In adult skeletal muscle, Notch signaling contributes to the maintenance of satellite cell (SC) quiescence and the proliferation of myoblasts after SC activation. To address the role of Poglut1 in myogenesis, we created two stable C2C12 cell lines where Poglut1 was downexpressed by 42% and 81%, and assessed their ability to differentiate. We showed that Poglut1 knockdown reduced Notch signaling and largely affected the key regulators of myogenic differentiation, with PAX7 decrease and MYOD increase. This perturbed Pax7/MyoD expression balance led to a premature myogenic differentiation and an increase in myotube size, accentuated in case of strong Poglut1 downexpression. Differences observed between myotubes of the two Poglut1 knockdown cell lines could reflect dissimilar fusion defects. We concluded that Poglut1 contributes to myogenesis by regulating Notch signaling and defining, directly or indirectly, the proportion of cells that commit differentiation.


Assuntos
Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Fibras Musculares Esqueléticas/fisiologia , Animais , Diferenciação Celular/fisiologia , Linhagem Celular , Fator de Crescimento Epidérmico , Camundongos , Desenvolvimento Muscular , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Proteína MyoD/metabolismo , Mioblastos/citologia , Receptores Notch/metabolismo , Transdução de Sinais
11.
Open Biol ; 6(9)2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27628322

RESUMO

Postnatal skeletal muscle growth results from the activation of satellite cells and/or an increase in protein synthesis. The Notch signalling pathway maintains satellite cells in a quiescent state, and once activated, sustains their proliferation and commitment towards differentiation. In mammals, POFUT1-mediated O-fucosylation regulates the interactions between NOTCH receptors and ligands of the DELTA/JAGGED family, thus initiating the activation of canonical Notch signalling. Here, we analysed the consequences of downregulated expression of the Pofut1 gene on postnatal muscle growth in mutant Pofut1(cax/cax) (cax, compact axial skeleton) mice and differentiation of their satellite cell-derived myoblasts (SCDMs). Pofut1(cax/cax) mice exhibited muscle hypertrophy, no hyperplasia and a decrease in satellite cell numbers compared with wild-type C3H mice. In agreement with these observations, Pofut1(cax/cax) SCDMs differentiated earlier concomitant with reduced Pax7 expression and decrease in PAX7(+)/MYOD(-) progenitor cells. In vitro binding assays showed a reduced interaction of DELTA-LIKE 1 ligand (DLL1) with NOTCH receptors expressed at the cell surface of SCDMs, leading to a decreased Notch signalling as seen by the quantification of cleaved NICD and Notch target genes. These results demonstrated that POFUT1-mediated O-fucosylation of NOTCH receptors regulates myogenic cell differentiation and affects postnatal muscle growth in mice.


Assuntos
Fucosiltransferases/metabolismo , Desenvolvimento Muscular , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/metabolismo , Mioblastos/fisiologia , Receptores Notch/metabolismo , Transdução de Sinais , Animais , Diferenciação Celular , Membrana Celular/metabolismo , Células Cultivadas , Fucosiltransferases/genética , Expressão Gênica , Hipertrofia , Ligantes , Camundongos , Camundongos Endogâmicos C3H , Proteína MyoD/genética , Proteína MyoD/metabolismo , Mioblastos/citologia , Fator de Transcrição PAX7/genética , Fator de Transcrição PAX7/metabolismo , Receptores Notch/genética , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/fisiologia , Células-Tronco
12.
Mol Cell Biol ; 35(2): 391-405, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25384974

RESUMO

The Notch signaling pathway plays a crucial role in skeletal muscle regeneration in mammals by controlling the transition of satellite cells from quiescence to an activated state, their proliferation, and their commitment toward myotubes or self-renewal. O-fucosylation on Notch receptor epidermal growth factor (EGF)-like repeats is catalyzed by the protein O-fucosyltransferase 1 (Pofut1) and primarily controls Notch interaction with its ligands. To approach the role of O-fucosylation in myogenesis, we analyzed a murine myoblastic C2C12 cell line downregulated for Pofut1 expression by short hairpin RNA (shRNA) inhibition during the time course of differentiation. Knockdown of Pofut1 affected the signaling pathway activation by a reduction of the amount of cleaved Notch intracellular domain and a decrease in downstream Notch target gene expression. Depletion in Pax7(+)/MyoD(-) cells and earlier myogenic program entrance were observed, leading to an increase in myotube quantity with a small number of nuclei, reflecting fusion defects. The rescue of Pofut1 expression in knockdown cells restored Notch signaling activation and a normal course in C2C12 differentiation. Our results establish the critical role of Pofut1 on Notch pathway activation during myogenic differentiation.


Assuntos
Fucosiltransferases/metabolismo , Mioblastos/citologia , Receptores Notch/metabolismo , Transdução de Sinais/fisiologia , Animais , Diferenciação Celular/fisiologia , Linhagem Celular , Técnicas de Silenciamento de Genes/métodos , Camundongos , Desenvolvimento Muscular/genética , Desenvolvimento Muscular/fisiologia , Fator de Transcrição PAX7/metabolismo
13.
BMC Genomics ; 10: 483, 2009 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-19843320

RESUMO

BACKGROUND: Several global transcriptomic and proteomic approaches have been applied in order to obtain new molecular insights on skeletal myogenesis, but none has generated any specific data on glycogenome expression, and thus on the role of glycan structures in this process, despite the involvement of glycoconjugates in various biological events including differentiation and development. In the present study, a quantitative real-time RT-PCR technology was used to profile the dynamic expression of 375 glycogenes during the differentiation of C2C12 myoblasts into myotubes. RESULTS: Of the 276 genes expressed, 95 exhibited altered mRNA expression when C2C12 cells differentiated and 37 displayed more than 4-fold up- or down-regulations. Principal Component Analysis and Hierarchical Component Analysis of the expression dynamics identified three groups of coordinately and sequentially regulated genes. The first group included 12 down-regulated genes, the second group four genes with an expression peak at 24 h of differentiation, and the last 21 up-regulated genes. These genes mainly encode cell adhesion molecules and key enzymes involved in the biosynthesis of glycosaminoglycans and glycolipids (neolactoseries, lactoseries and ganglioseries), providing a clearer indication of how the plasma membrane and extracellular matrix may be modified prior to cell fusion. In particular, an increase in the quantity of ganglioside GM3 at the cell surface of myoblasts is suggestive of its potential role during the initial steps of myogenic differentiation. CONCLUSION: For the first time, these results provide a broad description of the expression dynamics of glycogenes during C2C12 differentiation. Among the 37 highly deregulated glycogenes, 29 had never been associated with myogenesis. Their biological functions suggest new roles for glycans in skeletal myogenesis.


Assuntos
Diferenciação Celular/genética , Desenvolvimento Muscular/genética , Fibras Musculares Esqueléticas/metabolismo , Mioblastos/metabolismo , Animais , Linhagem Celular , Análise por Conglomerados , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Genoma , Glicosilação , Camundongos , Fibras Musculares Esqueléticas/citologia , Mioblastos/citologia , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética
14.
BMC Genomics ; 9: 151, 2008 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-18384666

RESUMO

BACKGROUND: The superfamily of serine proteinase inhibitors (serpins) is involved in numerous fundamental biological processes as inflammation, blood coagulation and apoptosis. Our interest is focused on the SERPINA3 sub-family. The major human plasma protease inhibitor, alpha1-antichymotrypsin, encoded by the SERPINA3 gene, is homologous to genes organized in clusters in several mammalian species. However, although there is a similar genic organization with a high degree of sequence conservation, the reactive-centre-loop domains, which are responsible for the protease specificity, show significant divergences. RESULTS: We provide additional information by analyzing the situation of SERPINA3 in the bovine genome. A cluster of eight genes and one pseudogene sharing a high degree of identity and the same structural organization was characterized. Bovine SERPINA3 genes were localized by radiation hybrid mapping on 21q24 and only spanned over 235 Kilobases. For all these genes, we propose a new nomenclature from SERPINA3-1 to SERPINA3-8. They share approximately 70% of identity with the human SERPINA3 homologue. In the cluster, we described an original sub-group of six members with an unexpected high degree of conservation for the reactive-centre-loop domain, suggesting a similar peptidase inhibitory pattern. Preliminary expression analyses of these bovSERPINA3s showed different tissue-specific patterns and diverse states of glycosylation and phosphorylation. Finally, in the context of phylogenetic analyses, we improved our knowledge on mammalian SERPINAs evolution. CONCLUSION: Our experimental results update data of the bovine genome sequencing, substantially increase the bovSERPINA3 sub-family and enrich the phylogenetic tree of serpins. We provide new opportunities for future investigations to approach the biological functions of this unusual subset of serine proteinase inhibitors.


Assuntos
Bovinos/genética , Cromossomos de Mamíferos/genética , Regulação da Expressão Gênica , Genômica , Família Multigênica/genética , alfa 1-Antiquimotripsina/genética , Sequência de Aminoácidos , Animais , Southern Blotting , Clonagem Molecular , Evolução Molecular , Humanos , Camundongos , Dados de Sequência Molecular , Músculos/metabolismo , Filogenia , Proteômica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Terminologia como Assunto , alfa 1-Antiquimotripsina/química
15.
J Plant Physiol ; 165(9): 1003-10, 2008 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-18160178

RESUMO

Two APETALA2 domain transcription factors were characterized first in angiosperms, and, recently, in several gymnosperms. These proteins are involved in several processes, from flowering to embryogenesis in Arabidopsis thaliana. We extrapolated this result to hybrid larch (Larixxmarschlinsii Coaz) resulting from a cross between European (Larix decidua) and Japanese (Larix kaempferi) larches. Somatic embryogenesis is well described and controlled for this Pinaceae. We characterized two-AP2 domain genes: LmAP2L1 and LmAP2L2. Phylogenetic analysis confirmed that LmAP2L1 and LmAP2L2 were orthologous to Norway spruce PaAP2L1 and PaAP2L2 and that L1 forms appeared to be specific to Pinaceae. RT-PCR analysis showed that larch APETALA2 was differentially expressed during late somatic embryogenesis and during the first steps of germination. Whereas LmAP2L2 was constitutively expressed during this process, LmAP2L1 expression appeared only during late somatic embryogenesis, when embryos were able to germinate. Further, LmAP2L1 appeared to be the preferentially expressed form during embryo germination. Thus, LmAP2L1 seems to be a valuable molecular marker for hybrid larch late somatic embryogenesis and could play a role during post-embryonic development.


Assuntos
Proteínas de Arabidopsis/química , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica de Plantas , Germinação/genética , Proteínas de Homeodomínio/química , Larix/embriologia , Larix/genética , Proteínas Nucleares/química , Proteínas de Plantas/genética , Sequência de Aminoácidos , Sequência Conservada , Cruzamentos Genéticos , Hibridização Genética , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/metabolismo , Estrutura Terciária de Proteína , Alinhamento de Sequência
16.
FEBS J ; 274(5): 1202-11, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17263732

RESUMO

O-Fucosylation is a post-translational glycosylation in which an O-fucose is covalently attached to the hydroxyl group of a specific serine or threonine residue. This modification occurs within the consensus sequence C2X(4-5)(S/T)C3 present on epidermal growth factor-like repeats of several proteins, including the Notch receptors and their ligands. The enzyme responsible for the addition of O-fucose to epidermal growth factor-like repeats is protein O-fucosyltransferase 1. Protein O-fucosyltransferase 1-mediated O-fucosylation is essential in Notch signaling, folding and targeting to the cell surface. Here, we studied the expression pattern of protein O-fucosyltransferase 1 in cattle and showed that the active enzyme is present in all tissues examined from embryo and adult as a glycoprotein with two N-glycans. By comparing protein O-fucosyltransferase 1 sequences available in databases, we observed that mammalian protein O-fucosyltransferase 1 enzymes possess two putative N-glycosylation sites, and that only the first is conserved among bilaterians. To gain more insight regarding the significance of N-glycans on protein O-fucosyltransferase 1, we substituted, by site-directed mutagenesis, bovine protein O-fucosyltransferase 1 N65, N163 or both, with L or Q. We demonstrated that the loss of N-glycan on N163 caused a slight decrease in protein O-fucosyltransferase 1 activity. In contrast, glycosylation of N65 was crucial for protein O-fucosyltransferase 1 functionality. Loss of glycosylation at N65 resulted in aggregation of protein O-fucosyltransferase 1, suggesting that N-glycosylation at this site is essential for proper folding of the enzyme.


Assuntos
Fucosiltransferases/química , Fucosiltransferases/metabolismo , Polissacarídeos/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Células COS , Bovinos , Chlorocebus aethiops , Sequência Conservada , Fucosiltransferases/análise , Fucosiltransferases/genética , Ácido Glutâmico/metabolismo , Glicosilação , Leucina/metabolismo , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Dobramento de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Solubilidade , Transfecção
17.
Glycobiology ; 14(4): 347-56, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14718375

RESUMO

All vertebrate alpha3- and alpha3/4-FUTs possess the characteristic acceptor-binding motif VxxHH(W/R)(D/E). FUT6 and FUTb enzymes, harboring R in the acceptor-binding motif, transfer fucose in alpha1,3 linkage, whereas FUT3 and FUT5 enzymes with W at the candidate position can also transfer fucose in alpha1,4 linkage-FUT3 being more efficient than FUT5. To determine the involvement of the W/R residue in acceptor recognition, we produced 34 variants of human FUT3, FUT5, FUT6, and ox FUTb Lewis enzymes. Among the FUT3 variants where W(111) was replaced by the other amino acids, only enzymes with an aromatic residue at the candidate position kept about 50% of alpha1,4 activity and showed no changes in K(m) values for GDP-Fuc donor and H-type 1 acceptor substrates. All other substitutions produced enzymes with less than 20% of the alpha1,4 activity. Thus the ability of alpha3/4-FUTs to recognize type 1 substrates involves the aromatic character of W in the acceptor-binding domain. The alpha1,3 activity of FUT6 and FUTb significantly decreased when their R residue was substituted by basic or charged residues. Moreover, FUT3 and FUT5 variants with W-->R substitution had a better affinity for H-type 2 substrate and higher alpha1,3 activities. Therefore the optimal fucose addition in alpha1,3 linkage requires the R residue in the acceptor-binding motif of Lewis FUTs.


Assuntos
Fucose/metabolismo , Fucosiltransferases/química , Fucosiltransferases/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Sequência de Bases , Humanos , Cinética , Mamíferos , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade , Especificidade por Substrato
18.
Mol Biol Evol ; 20(4): 513-21, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12654938

RESUMO

The mammalian Crx genes are highly divergent orthodenticle (otd)-related homeogenes that play important roles in the differentiation of retinal photoreceptors and the circadian entrainment. However, their evolutionary origin and orthological relationships with other otd-related genes remain unclear. An orthology relationship of these genes with the highly conserved Otx5 genes identified in fish and amphibians, and also expressed in the eye and epiphysis, has been proposed previously but remains controversial. To test this hypothesis, we have identified Crx genes in a wide range of mammals, including three marsupials, and Otx5-related genes in a lizard, a turtle, and two archosaurs (crocodile and chick), as well as in the pufferfish. Phylogenetic analyses of the coding sequences show that the mammalian Crx genes are orthologous to the Otx5-related genes isolated in other gnathostomes. They also indicate that a duplication event has taken place in actinopterygians, after the splitting of the Cladistia, and that a relaxation of the structural constraints acting on the gene coding region has occurred early in the mammalian lineage. This process may be linked not only to the loss of ancestral Otx5/Crx functions during gastrulation or in the retinal pigmented epithelium, but also to the evolution of photic entrainment mechanisms in mammals.


Assuntos
Ritmo Circadiano/genética , Evolução Molecular , Proteínas de Homeodomínio/genética , Células Fotorreceptoras/citologia , Transativadores/genética , Sequência de Aminoácidos , Animais , Diferenciação Celular , Cordados não Vertebrados/genética , Cação (Peixe)/genética , Peixes/genética , Duplicação Gênica , Variação Genética , Dados de Sequência Molecular , Fatores de Transcrição Otx , Filogenia , Homologia de Sequência de Aminoácidos , Proteínas de Peixe-Zebra
19.
Mol Biol Evol ; 19(6): 815-24, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12032237

RESUMO

In the animal kingdom the enzymes that catalyze the formation of alpha1,4 fucosylated-glycoconjugates are known only in apes (chimpanzee) and humans. They are encoded by FUT3 and FUT5 genes, two members of the Lewis FUT5-FUT3-FUT6 gene cluster, which had originated by duplications of an alpha3 ancestor gene. In order to explore more precisely the emergence of the alpha1,4 fucosylation, new Lewis-like fucosyltransferase genes were studied in species belonging to the three main primate groups. Two Lewis-like genes were found in brown and ruffed lemurs (prosimians) as well as in squirrel monkey (New World monkey). In the latter, one gene encodes an enzyme which transfers fucose only in alpha1,3 linkage, whereas the other is a pseudogene. Three genes homologous to chimpanzee and human Lewis genes were identified in rhesus macaque (Old World monkey), and only one encodes an alpha3/4-fucosyltransferase. The ability of new primate enzymes to transfer fucose in alpha1,3 or alpha1,3/4 linkage confirms that the amino acid R or W in the acceptor-binding motif "HH(R/W)(D/E)" is required for the type 1/type 2 acceptor specificity. Expression of rhesus macaque genes proved that fucose transfer in alpha1,4 linkage is not restricted to the hominoid family and may be extended to other Old World monkeys. Moreover, the presence of only one enzyme supporting the alpha1,4 fucosylation in rhesus macaque versus two enzymes in hominoids suggests that this function occurred twice independently during primate evolution.


Assuntos
Fucosiltransferases/genética , Primatas/genética , Sequência de Aminoácidos , Animais , Southern Blotting , Evolução Molecular , Fucosiltransferases/metabolismo , Humanos , Dados de Sequência Molecular , Filogenia , Primatas/metabolismo , Alinhamento de Sequência , Especificidade por Substrato
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