title: UBQLN1 interacts with SPEM1 and participates in spermiogenesis.
abstract: Spermiogenesis represents the process through which haploid male germ cells differentiate from round spermatids into elongated spermatids and eventually the male gametes called spermatozoa. Haploid cell differentiation is unique to male germ cell development and many unique genes/proteins essential for this process have been discovered. SPEM1 is one of these spermiogenesis-essential proteins encoded by a testis-specific gene exclusively expressed in the developing spermatids. Inactivation of Spem1 in mice results in deformed spermatozoa characterized by "head-bent-back" abnormalities with 100% penetrance. Using yeast two-hybrid screening assays, we identified UBQLN1 as one of the SPEM1-interacting partners. UBQLN1 and SPEM1 were colocalized to the manchette of elongating spermatids. Since UBQLN1 functions through binding and directing poly-ubiquitinated proteins to the proteasome for degradation, interactions between UBQLN1 and SPEM1 suggest a role in the regulation of protein ubiquitination during spermiogenesis.
authors.affiliation: Department of Embryology and Histology, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Bao
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Huili
authors.initials: H
authors.lastname: Zheng
authors.forename: Chen
authors.initials: C
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Yan
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000071183:Autophagy-Related Proteins; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000172:deficiency / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D011485:Protein Binding; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013087:Spermatids / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D013091:Spermatogenesis; D013737:Testis / Q000166:cytology / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D015854:Up-Regulation
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000071183:Autophagy-Related Proteins; D012333:RNA, Messenger; C538987:UBQLN1 protein, mouse; D004248:DNA (Cytosine-5-)-Methyltransferases; C519858:Spem1 protein, mouse