Linked Life Data

12112575

Source:http://linkedlifedata.com/resource/pubmed/id/12112575

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-7-11
pubmed:abstractText
We compared the secondary spermatogonia and the primary spermatocytes of Xenopus for the proteins in their microsomal fractions and identified a newly synthesized protein (94 kDa) and three other proteins (99, 85, and 72 kDa) which increased their amount after entering the meiotic phase. These four proteins were used as antigens to produce polyclonal antibody which was found to react with the four proteins as well as two other proteins (208 and 60 kDa). Immunoscreening of Xenopus testis cDNA library with this polyclonal antibody yielded two cDNA clones (Xmegs and Xtr) encoding novel proteins. Xmegs mRNA was specifically expressed in the spermatogenic cells from the mid-pachytene stage to completion of two meiotic divisions. The putative Xmegs protein contained 19 tandem repeats of 26 amino acid residues rich in proline as well as potential phosphorylation sites (i.e., serine and threonine residues). Around this repetitive area, we found five PEST sequences known as a proteolytic signal to target protein for degradation. The presence of PEST sequences was believed to allow protein levels to closely parallel mRNA abundance. These results suggested the possible role of this novel protein in the regulation of two meiotic divisions specific to the spermatogenesis in a phosphorylation- and/or dephosphorylation-dependent manner. On the other hand, Xtr mRNA was expressed in both spermatogenic and oogenic cells except for round spermatids and the later stage cells. This mRNA was also expressed in the early stage embryos and its amount was kept constant from the St. I oocyte to the gastrula stage and decreased thereafter. The putative Xtr protein contained four complete and one partial tudor-like domains that were discovered in Drosophila tudor protein which plays an important role in PGC differentiation and abdominal segmentation. The characteristic expression profile of Xtr and the protein structure similar to the Drosophila tudor protein suggested its possible role in the progression of meiosis and PGC differentiation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1040-452X
pubmed:author
pubmed:copyrightInfo
Copyright 2002 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:volume
62
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
421-30
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Two novel genes expressed in Xenopus germ line: characteristic features of putative protein structures, their gene expression profiles and their possible roles in gametogenesis and embryogenesis.
pubmed:affiliation
Department of Biological Science, Faculty of Science, Kumamoto University, Kurokami 2-39-1, Kumamoto, Japan.
pubmed:publicationType
Journal Article