Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mouse spermatogenic cells are known to express HSP70-2, a member of the HSP70 family of heat-shock proteins. The purpose of the present study was to characterize further the expression and localization of HSP70-2 in meiotic cells of mice and hamsters. After separating mouse spermatogenic cells into cytoplasmic and nuclear fractions, proteins were separated by two-dimensional gel electrophoresis and detected with HSP-specific antibodies. Of several HSP70 proteins identified in the cytoplasm, only HSC70 and HSP70-2 were also detected in the nucleus. Immunocytological analyses of spermatocyte prophase cells revealed that HSP70-2 was associated with the synaptonemal complex. Surface-spread synaptonemal complexes at pachytene and diplotene stages labeled distinctly with the antiserum to HSP70-2. Synaptonemal complexes from fetal mouse oocytes failed to show any evidence of HSP70-2. Reverse-transcriptase-polymerase chain reaction (RT-PCR) analyses of gene expression confirmed this sex specificity; Hsp70-2 mRNA was detected in mouse testes, but not ovaries. These findings are suggestive of a previously unsuspected sexual dimorphism in structure and/or function of the synaptonemal complex.
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PMID:HSP70-2 is part of the synaptonemal complex in mouse and hamster spermatocytes. 860 36

Recently, there have been several reports describing the cloning and characterization of the novel family of protein tyrosine phosphatase-like receptor molecules (known as IA-2 and PTP-NP/PTP-IAR/IA-2beta/phogrin), which may act as autoantigens in diabetes. Here, we report the molecular characterization and chromosomal localization of a new isoform of this family in brain termed PTP-NP-2 (for PTP-NP tyrosine phosphatase isoform), and its function in rat primary hippocampal neurons. PTP-NP-2 has 48% identity to IA-2. The principal difference between PTP-NP-2 and PTP-NP is a 17-amino-acid insert near the N-terminus of PTP-NP that is absent in PTP-NP-2. Genomic DNA analysis indicates that the 17-amino-acid insert is coded by a separate exon, suggesting that both IA-2beta and PTP-NP-2 are isoforms arising by alternate splicing of the same gene. Reverse transcriptase-PCR revealed that both isoforms are present in human SH-SY5Y neuroblastoma cells. PTP-NP-2 mRNA expression is highly restricted, with a 5.5-kb specific transcript in human fetal and adult brain and 5.5 and 3. 8 kb in human adult pancreas. SH-SY5Y neuroblastoma and U87-MG glioblastoma cells showed specific transcripts of 5.5 and 3.8<HSP SP = "0.25">kb, respectively, indicating the existence of several isoforms of this molecule in the nervous system. The human gene encoding PTP-NP-2 was assigned to human chromosome 7q22-qter using Southern blot analysis of genomic DNAs from rodent/human somatic hybrid cell lines. Confocal microscopy analyses of rat primary hippocampal neurons revealed that PTP-NP-2 is abundantly expressed on synaptic boutons in primary neurons. Wild-type PTP-NP-2 showed no measurable tyrosine phosphatase activity using an in-vitro pNPP assay. Examination of the PTP-NP-2 catalytic consensus sequence revealed that this sequence differed from the typical tyrosine phosphatase-domain consensus sequence by an alanine to aspartate change (amino acid 930). Mutation of aspartate 930 to alanine produced a catalytically active enzyme, suggesting that native PTP-NP and its isoform PTP-NP-2 are catalytically inactive receptor protein tyrosine phosphatase homologues. Taken together, these results indicate that the tyrosine phosphatase PTP-NP-2 is a new isoform of PTP-NP tyrosine phosphatase, is expressed on synaptic boutons and may participate in the regulation of synaptic bouton endocytosis.
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PMID:Characterization and chromosomal localization of PTP-NP-2, a new isoform of protein tyrosine phosphatase-like receptor, expressed on synaptic boutons. 971 34

The genetic variability and population structure of a collection of 45 Grapevine leafroll-associated virus 3 (GLRaV-3) isolates were studied by single-stranded conformation polymorphism (SSCP) and sequence analysis of the RNA-dependent RNA polymerase (RdRp), heat-shock protein 70 homologue (HSP-70) and coat protein (CP) genes. The distribution of SSCP profiles was not correlated with the geographical origin of the isolates, indicating that GLRaV-3 is a single, undifferentiated population. The majority of the isolates showed an SSCP profile and a population structure that were composed of a single predominant variant. However, 10% of the isolates for the RdRp and HSP-70 genes and 15% for the CP gene were composed of a combination of two or more variants. Estimation of genetic diversity and phylogenetic analysis disclosed the possible existence of vines with mixed infections by diverging sequence variants, showing, in some cases, possible recombination events. Furthermore, differences in the genetic diversity and constraints existing in the three regions analysed indicated a higher variability in the CP gene. The epidemiological and biological implications of this finding are discussed.
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PMID:Genetic variability and population structure of Grapevine leafroll-associated virus 3 isolates. 1560 49

Schistosomes are the causative agent of schistosomiasis. The 70-kDa heat-shock proteins (HSP70) are considered the predominant HSP family and play a key regulatory role in parasite development and pathogenesis. Based on the published sequences in Genbank/EMBL, an open-reading frame (ORF) encoding 653 amino acids (XP_002581385.1) and belonging to the Schistosoma HSP70 protein family with a molecular weight of 71.49 kDa was identified by bioinformatic analysis. Since the sequence shared 77% identity with the published full-length Homo sapiens HSP70 protein, it was named Schistosoma mortalin-like protein (MLP/Hsp70). Here, we report the molecular and functional characterization of the Schistosoma japonicum SjMLP/hsp70 as a member of the HSP70 family. The complete SjMLP/hsp70 coding sequence was amplified from a S. japonicum adult worm cDNA library by polymerase chain reaction (PCR) and subcloned into the pET28a expression vector. The purified recombinant protein, rSjMLP/hsp70, was identified as a member of 70-kDa HSP family by mass spectrometry and could be recognized by the S. japonicum-infected mouse serum. Reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting analysis revealed that SjMLP/hsp70 was widely expressed in the eggs, cercariae, schistosomula, and adult worms of S. japonicum. A thermotolerance assay showed that rSjMLP/hsp70 could protect Escherichia coli cells from heat damage. This chaperone-like activity was demonstrated by full-length SjMLP/hsp70. The detection of specific antibody levels by indirect enzyme-linked immunosorbent assay and IFN-gamma secretion of splenocytes by ELISpot assay suggested that mice immunized with SjMLP/hsp70 were able to elicit Th1-type bias immune response. The challenge-protective experiment showed that DNA vaccine of SjGST combined with SjMLP/hsp70 could induce a 31.31% reduction of worm burden and 58.59% reduction of egg burden in intestinal tissue of immunized mice. Our results imply that SjMLP/hsp70 has a potential adjuvant function and might be a vaccine candidate for schistosomiaisis, which is the first report of the expression and preliminary characterization analysis of this molecule.
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PMID:Molecular and functional characterization of a mortalin-like protein from Schistosoma japonicum (SjMLP/hsp70) as a member of the HSP70 family. 2060 14