STK31(TDRD8) is dynamically regulated throughout mouse spermatogenesis and interacts with MIWI protein.
Tudor-domain-containing proteins (TDRDs) are suggested to be critical regulators of germinal granules assembly involved in Piwi-interacting RNAs (piRNAs)-mediated pathways, of which associated components and the underlying functional mechanisms, however, remain to be elucidated. We herein characterized the expression pattern of STK31, a member of TDRDs subfamily (also termed as TDRD8), throughout spermatogenesis during mouse postnatal development. RT-PCR and Western blot verified its preferential expression in testis, but not in any other somatic tissues, in addition to embryonic stem cells. Immunofluorescent staining demonstrated that STK31 was confined to granules-like structures in mid-to-late spermatocyte cytoplasm and to acrosomal cap starting at steps 7-8 of spermatids. Furthermore, STK31 retained its localization to equatorial segment of acrosome during epididymal maturation, capacitation, and acrosome reaction. Co-immunoprecipitation assay in vivo and in vitro confirmed MIWI is a bona fide partner of STK31 in mice testes, in combination with LC/MS identification. We also discovered a group of heat shock proteins specifically associated with STK31 in vivo. Our findings suggest mouse STK31 could be a potential nuage-associated protein in the cytoplasm of mid-to-late spermatocytes and play pivotal roles related to fertilization.
Shanghai Key Laboratory for Reproductive Medicine, Department of Histology and Embryology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
Jianqiang
J
Bao
Li
L
Wang
Jianbo
J
Lei
Yanqin
Y
Hu
Yue
Y
Liu
Hongbin
H
Shen
Wei
W
Yan
Chen
C
Xu
D020101:Acrosome Reaction / Q000502:physiology; D000818:Animals; D060565:Argonaute Proteins / Q000378:metabolism*; D002460:Cell Line; D003593:Cytoplasm / Q000201:enzymology; D004822:Epididymis / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D007985:Leydig Cells / Q000166:cytology / Q000201:enzymology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013075:Sperm Capacitation / Q000502:physiology; D013087:Spermatids / Q000166:cytology / Q000201:enzymology; D013090:Spermatocytes / Q000166:cytology / Q000201:enzymology*; D013091:Spermatogenesis / Q000502:physiology*; D013379:Substrate Specificity / Q000502:physiology
D060565:Argonaute Proteins; C448522:Piwil1 protein, mouse; D012333:RNA, Messenger; D017346:Protein Serine-Threonine Kinases; C572900:STK31 protein, mouse