RESUMO
The COST Action Phycomorph (FA1406) was initiated in 2015 from a handful of academic researchers, and now joins together 19 European countries and nine international partners. Phycomorph's goal is to coordinate and develop research on developmental biology in macroalgae. This is an ambitious project, as the related scientific community is small, the concepts are complex, and there is currently limited knowledge of these organisms and there are few technologies to study them. Here we report the first step in achieving this enterprise, the creation of the Phycomorph network. We share the associated strengths, pitfalls, and prospects for setting up the network in the hope that this might guide similar efforts in other fields.
Assuntos
Cooperação Internacional , Pesquisa , PlantasRESUMO
We describe a multifunctional inositol polyphosphate kinase/phosphotransferase from Solanum tuberosum, StITPKalpha (GenBank accession number: EF362784), hereafter called StITPK1. StITPK1 displays inositol 3,4,5,6-tetrakisphosphate 1-kinase activity: K(m) = 27 microM, and V(max) = 19 nmol min(-1) mg(-1). The enzyme displays inositol 1,3,4,5,6-pentakisphosphate 1-phosphatase activity in the absence of a nucleotide acceptor and inositol 1,3,4,5,6-pentakisphosphate-ADP phosphotransferase activity in the presence of physiological concentrations of ADP. Additionally, StITPK1 shows inositol phosphate-inositol phosphate phosphotransferase activity. Homology modelling provides a structural rationale of the catalytic abilities of StITPK1. Inter-substrate transfer of phosphate groups between inositol phosphates is an evolutionarily conserved function of enzymes of this class.
Assuntos
Difosfato de Adenosina/química , Fosfatos de Inositol/química , Fosfotransferases (Aceptor do Grupo Álcool)/química , Proteínas de Plantas/química , Solanum tuberosum/enzimologia , Sequência de Aminoácidos , Catálise , Clonagem Molecular , Dados de Sequência Molecular , Monoéster Fosfórico Hidrolases/química , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Proteínas de Plantas/genética , Estrutura Secundária de Proteína , Especificidade por SubstratoRESUMO
The Arabidopsis genome encodes a family of inositol 1,3,4-trisphosphate 5/6-kinases which form a subgroup of a larger group of ATP-grasp fold proteins. An analysis of the inositol 1,3,4-trisphosphate 5/6-kinase family might, ultimately, be best rewarded by detailed comparison of related enzymes in a single genome. The enzyme encoded by At2G43980, AtITPK4; is an outlier to its family. At2G43980 is expressed in male and female organs of young and mature flowers. AtITPK4 differs from other family members in that it does not display inositol 3,4,5,6-tetrakisphosphate 1-kinase activity; rather, it displays inositol 1,4,5,6-tetrakisphosphate and inositol 1,3,4,5-tetrakisphosphate isomerase activity.
Assuntos
Trifosfato de Adenosina/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Fosfotransferases (Aceptor do Grupo Álcool)/química , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Flores/citologia , Flores/enzimologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Glucuronidase/metabolismo , Hibridização In Situ , Cinética , Dados de Sequência Molecular , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Regiões Promotoras Genéticas/genética , Estrutura Secundária de Proteína , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Especificidade por SubstratoRESUMO
Inositol phosphates and the enzymes that interconvert them are key regulators of diverse cellular processes including the transcriptional machinery of arginine synthesis [York (2006) Biochim. Biophys. Acta 1761, 552-559]. Despite considerable interest and debate surrounding the role of Saccharomyces cerevisiae inositol polyphosphate kinase (ScIPK2, ARG82, ARGRIII) and its inositol polyphosphate products in these processes, there is an absence of data describing how the transcripts of the arginine synthetic pathway, and the amino acid content of ScIpk2Delta, are altered under different nutrient regimes. We have cloned an IPMK (inositol phosphate multikinase) from Solanum tuberosum, StIPMK (GenBank(R) accession number EF362785), that despite considerable sequence divergence from ScIPK2, restores the arginine biosynthesis pathway transcripts ARG8, acetylornithine aminotransferase, and ARG3, ornithine carbamoyltransferase of ScIpk2Delta yeast to wild-type profiles. StIPMK also restores the amino acid profiles of mutant yeast to wild-type, and does so with ornithine or arginine as the sole nitrogen sources. Our data reveal a lysine accumulation phenotype in ScIpk2Delta yeast that is restored to a wild-type profile by expression of StIPMK, including restoration of the transcript profiles of lysine biosynthetic genes. The StIPMK protein shows only 18.6% identity with ScIPK2p which probably indicates that the rescue of transcript and diverse amino acid phenotypes is not mediated through a direct interaction of StIPMK with the ArgR-Mcm1 transcription factor complex that is a molecular partner of ScIPK2p.
