title: Developmental expression of p97/VCP (Valosin-containing protein) and Jab1/CSN5 in the rat testis and epididymis.
abstract: BACKGROUND
  The ubiquitin proteasome system (UPS) is a key player in regulating many cellular processes via proteasomal degradation of ubiquitinated proteins. Recently published data show that Jab1/CSN5 interacts with p97/VCP and controls the ubiquitination status of proteins bound to p97/VCP in mouse and human cells. However, coexpression of p97/VCP and Jab1/CSN5 in the developing rat testis and epididymis has not previously been studied.
  
  
  METHODS
  Testicular and epididymal tissues from 5-, 15-, 30-, and 60-day-old rats were examined by immunohistochemistry and Western blotting. Colocalisation of proteins was determined by immunofluorescence microscopy.
  
  
  RESULTS
  In the 5-day-old rat testis, p97/VCP and Jab1/CSN5 were specifically expressed in gonocytes. The expression of p97/VCP and Jab1/CSN5 significantly increased at day 15 and was found in spermatogonia, Sertoli cells and spermatocytes. In 30- and 60-day-old rat testes, p97/VCP indicated moderate to strong expression in Sertoli cells, spermatogonia, round and elongating spermatids. However, moderate to weak expression was observed in spermatocytes. Jab1/CSN5 showed strong expression in spermatogonia and spermatocytes, while relatively moderate expression was observed in round and elongating spermatids in 30- and 60-day-old rat testes. In contrast, in the epididymis, the expression of both proteins gradually increased from 5 to 60 days of age. After rats reached 2 weeks of age, the expression of both proteins was mostly restricted to the basal and principal cells of the caput epididymis.
  
  
  CONCLUSIONS
  Our study suggests that p97/VCP and Jab1/CSN5 could be an important part of the UPS in the developing rat testis and epididymis and that both proteins may be involved in the regulation of spermatogenesis and epididymal epithelial functions.
authors.affiliation: Department of Histology and Embryology, Faculty of Medicine, Gaziosmanpasa University, Tokat, Turkey. sevilcayli@yahoo.com
authors.forename: Sevil
authors.initials: S
authors.lastname: Cayli
authors.forename: Seda
authors.initials: S
authors.lastname: Ocakli
authors.forename: Fikret
authors.initials: F
authors.lastname: Erdemir
authors.forename: Ufuk
authors.initials: U
authors.lastname: Tas
authors.forename: Huseyin
authors.initials: H
authors.lastname: Aslan
authors.forename: Tamer
authors.initials: T
authors.lastname: Yener
authors.forename: Zafer
authors.initials: Z
authors.lastname: Karaca
mesh_terms: D000251:Adenosine Triphosphatases / Q000096:biosynthesis* / Q000235:genetics; D000818:Animals; D000075686:COP9 Signalosome Complex; D018797:Cell Cycle Proteins / Q000096:biosynthesis* / Q000235:genetics; D004822:Epididymis / Q000254:growth & development / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013737:Testis / Q000254:growth & development / Q000378:metabolism*; D000074405:Valosin Containing Protein
chemical_list: D018797:Cell Cycle Proteins; C490121:Gps1 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; D000075686:COP9 Signalosome Complex; D000251:Adenosine Triphosphatases; C000614178:VCP protein, human; D000074405:Valosin Containing Protein; C000614179:Vcp protein, mouse; C000614180:Vcp protein, rat