title: Regulated expression of the ubiquitin protein ligase, E3(Histone)/LASU1/Mule/ARF-BP1/HUWE1, during spermatogenesis.
abstract: A ubiquitin protein ligase (E3), E3(Histone)/LASU1 (Mule/ARF-BP1/HUWE1), was recently identified that mediates ubiquitination of core histones, the Mcl-1 anti-apoptotic protein, and the p53 tumor suppressor protein. However, the expression of E3(Histone)/LASU1 remains poorly studied. Because we identified E3(Histone)/LASU1 from the testis, we explored its regulation during spermatogenesis. In the first wave of rat spermatogenesis, E3(Histone)/LASU1 mRNA and protein had peak expression at days 10 and 20, respectively, and decreased with age. Consistent with these findings, immunohistochemistry revealed that E3(Histone)/LASU1 was highly expressed in nuclei from spermatogonia to mid-pachytene spermatocytes. There was no obvious staining in spermatids, when histones are ubiquitinated and degraded. E3(Histone)/LASU1 was also expressed in other tissues. However, except in neuronal cells of the brain, expression was cytoplasmic. Thus, E3(Histone)/LASU1 may play a role in chromatin modification in early germ cells of the testis, but also has functions in other tissues.
authors.affiliation: Department of Biochemistry, McGill University, Montreal, Quebec, Canada.
authors.forename: Zhiqian
authors.initials: Z
authors.lastname: Liu
authors.forename: Dengsheng
authors.initials: D
authors.lastname: Miao
authors.forename: Qingwen
authors.initials: Q
authors.lastname: Xia
authors.forename: Louis
authors.initials: L
authors.lastname: Hermo
authors.forename: Simon S
authors.initials: SS
authors.lastname: Wing
mesh_terms: D000818:Animals; D015870:Gene Expression; D008297:Male; D051379:Mice; D051381:Rats; D017207:Rats, Sprague-Dawley; D013090:Spermatocytes / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D013091:Spermatogenesis; D013737:Testis / Q000166:cytology / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000302:isolation & purification / Q000378:metabolism*