Expression of a part of the Potato virus A non-structural protein P3 in Escherichia coli for the purpose of antibody preparation and P3 immunodetection in plant material.

The N-terminal part of the Potato virus A (PVA) P3 protein was cloned into two E. coli fusion expression systems. An overexpression of the P3 fragment fused with thioredoxin was observed between 2 and 21 h after induction. The protein formed insoluble inclusions. Decreasing the cultivation temperature did not enhance its solubility. To obtain antigen for antibody preparation, inclusions were concentrated and purified by sucrose gradient centrifugation, and subjected to SDS-polyacrylamide gel electrophoresis. The band specific for the protein was excised from the gel and used for rabbit immunization. Obtained antibody tested positive with high specificity in immunoblots of expressed PVA P3 fused with either thioredoxin or GST. The antibody was also applied for the detection of P3 protein in plant material by immunoblot. Previous plant sap concentration was essential for most samples. Three concentration methods were tested: simple centrifugal size-exclusion filtration, the same preceded with high-speed centrifugation at 250,000 x g, and differential ammonium sulfate precipitation. The last approach was the most convenient. Plants tested included PVA P3-transgenic tobacco lines as well as PVA-infected wild-type tobacco. In all cases, mature P3 with a molecular mass of 40 kDa was detected.

Apisimin, a new serine-valine-rich peptide from honeybee (Apis mellifera L.) royal jelly: purification and molecular characterization.

A peptide named apisimin was found in honeybee (Apis mellifera L.) royal jelly (RJ). N-terminal sequencing showed that this peptide corresponded to the sequence of a cDNA clone isolated from an expression cDNA library prepared from heads of nurse honeybees. No homology was found between the protein sequence of apisimin with a molecular mass of 5540.4 Da and sequences deposited in the Swiss-Prot database. The 54 amino acids of apisimin do not include Cys, Met, Pro, Arg, His, Tyr, and Trp residues. The peptide shows a well-defined secondary structure as observed by CD spectroscopy, and has the tendency to form oligomers. Isoelectrofocusing showed apisimin to be an acidic peptide.

Muscarinic acetylcholine receptors induce the expression of the immediate early growth regulatory gene CYR61.

In brain, muscarinic acetylcholine receptors (mAChRs) modulate neuronal functions including long term potentiation and synaptic plasticity in neuronal circuits that are involved in learning and memory formation. To identify mAChR-inducible genes, we used a differential display approach and found that mAChRs rapidly induced transcription of the immediate early gene CYR61 in HEK 293 cells with a maximum expression after 1 h of receptor stimulation. CYR61 is a member of the emerging CCN gene family that includes CYR61/CEF10, CTGF/FISP-12, and NOV; these encode secretory growth regulatory proteins with distinct functions in cell proliferation, migration, adhesion, and survival. We found that CYR61, CTGF, and NOV were expressed throughout the human central nervous system. Stimulation of mAChRs induced CYR61 expression in primary neurons and rat brain where CYR61 mRNA was detected in cortical layers V and VI and in thalamic nuclei. In contrast, CTGF and NOV expression was not altered by mAChRs neither in neuronal tissue culture nor rat brain. Receptor subtype analyses demonstrated that m1 and m3 mAChR subtypes strongly induced CYR61 expression, whereas m2 and m4 mAChRs had only subtle effects. Increased CYR61 expression was coupled to mAChRs by both protein kinase C and elevations of intracellular Ca(2+). Our results establish that CYR61 expression in mammalian brain is under the control of cholinergic neurotransmission; it may thus be involved in cholinergic regulation of synaptic plasticity.

The family of major royal jelly proteins and its evolution.

A cDNA encoding a new member of the gene family of major royal jelly proteins (MRJPs) from the honeybee, Apis mellifera, was isolated and sequenced. Royal jelly (RJ) is a secretion of the cephalic glands of nurse bees. The origin and biological function of the protein component (12.5%, w/w) of RJ is unknown. We show that the MRJP gene family encodes a group of closely related proteins that share a common evolutionary origin with the yellow protein of Drosophila melanogaster. Yellow protein functions in cuticle pigmentation in D. melanogaster. The MRJPs appear to have evolved a novel nutritional function in the honeybee.

Molecular characterization of MRJP3, highly polymorphic protein of honeybee (Apis mellifera) royal jelly.

Major proteins of honey bee (Apis mellifera) royal jelly are members of the MRJP protein family. One MRJP protein termed MRJP3 exhibits a size polymorphism as detected by SDS-PAGE. In this report we show that polymorphism of the MRJP3 protein is a consequence of the polymorphism of a region with a variable number of tandem repeats (VNTR) located at the C-terminal part of the MRJP3 coding region. We present the characterization of five polymorphic alleles of MRJP3 by DNA sequencing. By PCR analyses, at least 10 alleles of distinct sizes were found in randomly sampled bees. Studies with nurse bees from a single honeybee colony revealed both Mendelian inheritance and very high variability of the MRJP3 genomic locus. The high variability and simple detection of the MRJP3 polymorphism may be useful for genotyping of individuals in studies of the honeybee.

A family of major royal jelly proteins of the honeybee Apis mellifera L.

The characterization of major proteins of honeybee larval jelly (49-87 kDa) was performed by the sequencing of new complementary DNAs (cDNAs) obtained from a honeybee head cDNA library, by the determination of N-terminal sequences of the proteins, and by analyses of the newly obtained and known sequence data concerning the proteins. It was found that royal jelly (RJ) and worker jelly (WJ) contain identical major proteins and that all the proteins belong to one protein family designated MRJP (from Major Royal Jelly Proteins). The family consists of five main members (MRJP1, MRJP2, MRJP3, MRJP4, MRJP5). The proteins MRJP3 and MRJP5 are polymorphic. MRJPs account for 82 to 90% of total larval jelly protein, and they contain a relatively high amount of essential amino acids. These findings support the idea that MRJPs play an important role in honeybee nutrition.

Production and purification of Japanese quail ovalbumin as fusion protein with glutathione S-transferase in Escherichia coli.

A plasmid encoding a fusion protein interlinked by thrombin recognition sequence between glutathione S-transferase and Japanese quail ovalbumin (without 40 amino acid residues from the 5'-end of the ORF) has been constructed, employing the expression system pGEX-2T. The deglycosylated fusion protein (64 kDa) was purified by affinity chromatography on glutathione agarose beads, analyzed by SDS-polyacrylamide gel electrophoresis, immunochemically detected with antiserum raised against Japanese quail ovalbumin and tested for its stability.

Characterization by cDNA cloning of two new human protein kinases. Evidence by sequence comparison of a new family of mammalian protein kinases.

Two new human cDNAs, designated phclk2 and phclk3, which have a high identity to the cDNA of the human protein kinase clk, were characterized. Typical features of hclk2 and hclk3 proteins are non-homologous N-terminal regions and the presence of the C-terminal protein kinase domain, which is characteristic for serine/threonine-type kinases. We also identified the differentially spliced forms phclk2(139) and phclk3(152) with deletions of 88 and 97 nt, respectively, which lead to changes in the open reading frames. hclk2(139) and hclk3(152) proteins do not possess a protein kinase domain and are nearly identical to the N-terminal regions of the above-mentioned protein kinases. We verified that differentially spliced variants also exist for hclk1 as well as for a mouse clk protein kinase. It was shown that shorter and longer alternatively spliced mRNAs co-exist in different human tissues. According to Southern analysis, hclk2 and hclk3 appear to be specified by single copy genes. The genes for hclk2 as well as for hclk3 were localized to human chromosomes 1 and 15, respectively.

A human amyloid precursor-like protein is highly homologous to a mouse sequence-specific DNA-binding protein.

From a cDNA sequence, we have deduced the amino acid sequence for a human amyloid precursor-like protein (APPH) with > 92% identity to the CDEI binding protein (CDEBP) of the mouse and the fragmentary rat protein YWK-II of unknown function. Expression of APPH was found in all tissues examined. A striking homology of APPH to human amyloid precursor protein (APP) was observed. Overall identity accounts for 52.7%. However, there are three domains of APPH with remarkably higher similarities, corresponding to amino acid sequence positions 47-204 (76.6%), 308-567 (67.7%), and 694-763 (69.9%). Using an APPH antiserum, we localized APPH in nuclei of human interphase cells and found an increased synthesis of APPH in mitotic cells. Our results indicate that the highly conserved proteins human APPH, mouse CDEBP, and rat YWK-II are apparently homologues of a CDEI binding protein with indispensible function in mammalian genome segregation.

Porcine luteal cells express monocyte chemoattractant protein-2 (MCP-2): analysis by cDNA cloning and northern analysis.

From an expression library in lambda UniZAP, derived from porcine corpus luteum (CL), a clone lambda MCP9 was detected by hybridization with a porcine MCP-1 specific probe. A pBluescriptSK-derivative pMCP9 was generated from lambda MCP9 by in vivo excision and was shown to contain an open reading frame (ORF) encoding a protein highly homologous to bovine monocyte chemoattractant protein-2 (MCP-2). Comparison of amino acid sequences of known MCPs identified the protein encoded by pMCP9 as porcine MPC-2. The 3' untranslated region of pMCP9 was completed by 3' RACE. Northern analysis using RNA from porcine luteal cells and probes specific for porcine MCP-1 and MCP-2 revealed that porcine luteal cells express both MCPs. According to Southern analysis MCP-2, like MCP-1, is specified by a single copy gene.

The gene for the amyloid precursor-like protein APLP2 is assigned to human chromosome 11q23-q25.

The human amyloid precursor-like protein APLP2 is a highly conserved homologue of a sequence-specific DNA-binding mouse protein with a predicted function in the cell cycle. Somatic cell hybrids segregating human chromosomes were used to assign the APLP2 gene to chromosome 11. Fluorescence in situ hybridization confirmed this assignment and further localized the gene to q23-q25.

Porcine luteal cells express monocyte chemoattractant protein-1 (MCP-1): analysis by polymerase chain reaction and cDNA cloning.

RT PCR employing poly(A+)RNA from porcine luteal cells and a combination of primers designed from the known bovine MCP-1 cDNA identified the luteal cells as a source of MCP-1. This finding is corroborated by results from Northern analysis using total RNA from luteal cells. To characterize the complete porcine MCP-1 cDNA, poly (A+)RNA was isolated from porcine corpus luteum, transcribed into cDNA and the latter cloned into the expression vector lambda Uni-ZapXR. A digoxigenin-labeled DNA probe of 375 bp was obtained by PCR and employed to screen the library. From the positive clones pMCP5, pMCP7 and pMCP10, the clone pMCP5 was selected and both strands of the cDNA insert were sequenced. The cDNA insert was 742 bp long, with an open reading frame (ORF) encoding a protein of 99 amino acid residues which by comparison with known amino acid sequences of MCPs yielded highest identities with MCP-1 sequences. We therefore assume that pMCP5 encodes the amino acid sequence for porcine MCP-1.

Characterization by cDNA cloning of the mRNA of human ribosomal protein L8.

From a lambda UNI-ZAP XR cDNA library derived from poly(A)+RNA of human ovarian granulosa cells a cDNA clone pHG51 was isolated. Sequence analysis showed significant homology to the C-terminal region of rat ribosomal protein L8 cDNA. The 5'-end of the cDNA was completed by PCR with cloned total cDNA. Aligning of DNA sequences from PCR clones with the sequence of the pHG51 insert yielded the full-length cDNA. From the open reading frame of the cDNA an amino acid sequence for a polypeptide of 257 residues was derived, which was identical with rat ribosomal protein L8 and also possessed a high degree of identity to ribosomal proteins L8 of other species. It is therefore assumed that the characterized cDNA represents the mRNA of the human ribosomal protein L8. Southern analysis revealed that human ribosomal protein L8 is specified by multi copy genes.

Characterization by cDNA cloning of the mRNA of a highly basic human protein homologous to the yeast ribosomal protein YL41.

From a cDNA library in lambda gt11 derived from poly(A)+ mRNA of human ovarian granulosa cells, a cDNA clone lambda HG12.1, containing an EcoRI insert of 470 bp, was identified. After subcloning of the insert into pUC18, the clone pHG12.1 was obtained and sequenced. The 5'-region of the insert of pHG12.1 was extended by the polymerase chain reaction (PCR) with cloned total cDNA. Assembly of the PCR fragment with the insert of pHG12.1 yielded clone pHG12. From the first open reading frame of pHG12 the amino acid sequence for a polypeptide of 25 amino acid residues (designated HG12) was derived, which was identical in 22 residues with yeast ribosomal protein YL41. It is therefore assumed that HG12 is the first mammalian homolog of yeast ribosomal protein YL41. Transcription of DNA fragments containing the coding region of pHG12 cloned into BluescriptM13, followed by cell-free translation, yielded a polypeptide with an apparent mol.wt. of 14.5 kDa, much larger than the theoretical mol.wt. (3454 Da). The discrepancy between theoretical and apparent mol.wt. was also observed for yeast ribosomal protein YL41. Southern analysis revealed that HG12 is not specified by a single copy gene. Homology for HG12 specific sequences is observed for bovine, porcine and rat species.

Expression of Japanese quail ovalbumin in Saccharomyces cerevisiae.

A cDNA sequence coding for Japanese quail ovalbumin was used for the construction of expression plasmid under the ADH1 promoter of the yeast shuttle vector pVT101-U. The resulting recombinant expression vector pJK2 was used for the transformation of Saccharomyces cerevisiae. Expression of quail ovalbumin in yeast cells was demonstrated by Western blotting followed by immunochemical detection.

Human elongation factor 1 beta: cDNA and derived amino acid sequence.

From a cDNA library in lambda gt11 derived from poly (A+)RNA of human ovarian granulosa cells a cDNA clone lambda HGP34, containing an EcoRI insert of 829 bp, was identified. After subcloning of the insert into pUC18, the clone pHGP34 was obtained and sequenced. The derived amino acid sequence, corresponding to a protein of 225 amino acids, shows a high degree of homology to elongation factor 1 beta (EF-1 beta) of Artemia salina (57%) and known peptide sequences of Xenopus laevis EF-1 beta (86%). We therefore assume that the protein coded for by pHGP34 represents human EF-1 beta. Northern analysis reveals an EF-1 beta specific mRNA of 900 bp. Southern analysis indicates that EF-1 beta in the human genome, like EF-1 alpha, appears to be specified by more than one gene. A high degree of sequence homology for EF-1 beta specific sequences is observed for bovine, rat and mouse species.

Characterization of three abundant mRNAs from human ovarian granulosa cells.

Three cDNA clones, pHGR122, pHGR11, and pHGR74 containing the coding information for abundant mRNAs were identified from a human ovarian granulosa cell cDNA library. Characterization by nucleotide sequencing revealed that pHGR122 was specific for a collagenase inhibitor and pHGR11 for melanoma-associated antigen ME491. Relative quantification by Northern analysis indicated that collagenase inhibitor mRNA is a major species in granulosa cells. This finding provides evidence for the origin of this protein in follicular fluid as a secretory product of granulosa cells. pHGR11 identified melanoma-associated antigen ME491 as the unexpected product of normal, noncarcinogenic, granulosa cells. pHGR74 has the complete coding information for an unknown protein. Three independent experiments: (i) cell-free translation of pHGR74 RNA; (ii) transcription of suitable restriction fragments followed by cell-free translation; (iii) hydrolysis of the cell-free translation product of pHGR74 RNA by endoproteinase Lys-C, identified one open reading frame coding for an acidic, highly hydrophilic protein of 111 amino acid residues. pHGR74 mRNA is expressed in human testis, prostate, seminal vesicle, and ovarian granulosa cells. A comparative Southern analysis indicates pHGR74 mRNA is species specific and encoded by a single-copy gene.

Complete sequence of the coding region of human elongation factor 2 (EF-2) by enzymatic amplification of cDNA from human ovarian granulosa cells.

The use of two primers allowed the specific enzymatic amplification of elongation factor 2 starting with total double-stranded cDNA from human ovarian granulosa cells. The amplified DNA fragment with a length of 1765 bp was restricted and sequenced by the shot gun approach. From the sequences obtained from the amplified fragment and the cDNA insert of pHGR81 [Rapp et al. (1988) Biol. Chem. Hoppe-Seyler 369, 247-250] respectively, the DNA sequence containing the complete coding as well as the 3'-untranslated region was assembled.