Developmental regulation of ubiquitin C-terminal hydrolase isozyme expression during spermatogenesis in mice.
The ubiquitin pathway functions in the process of protein turnover in eukaryotic cells. This pathway comprises the enzymes that ubiquitinate/deubiquitinate target proteins and the proteasome that degrades ubiquitin-conjugated proteins. Ubiquitin C-terminal hydrolases (UCHs) are thought to be essential for maintaining ubiquitination activity by releasing ubiquitin (Ub) from its substrates. Mammalian UCH-L1 and UCH-L3 are small proteins that share considerable homology at the amino acid level. Both of these UCHs are highly expressed in the testis/ ovary and neuronal cells. Our previous work demonstrated that UCH-L1-deficient gracile axonal dystrophy (gad) mice exhibit progressively decreasing spermatogonial stem cell proliferation, suggesting that UCH isozymes in the testis function during spermatogenesis. To analyze the expression patterns of UCH isozymes during spermatogenesis, we isolated nearly homogeneous populations of spermatogonia, spermatocytes, spermatids, and Sertoli cells from mouse testes. Western blot analysis detected UCH-L1 in spermatogonia and Sertoli cells, whereas UCH-L3 was detected in spermatocytes and spermatids. Moreover, reverse transcription-polymerase chain reaction analysis of UCH isozymes showed that UCH-L1 and UCH-L4 mRNAs are expressed in spermatogonia, whereas UCH-L3 and UCH-L5 mRNAs are expressed mainly in spermatocytes and spermatids. These results suggest that UCH-L1 and UCH-L3 have distinct functions during spermatogenesis, namely, that UCH-L1 may act during mitotic proliferation of spermatogonial stem cells whereas UCH-L3 may function in the meiotic differentiation of spermatocytes into spermatids.
Kwon
Jungkee
J
Department of Biomedical Science, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Wang
Yu-Lai
YL
Setsuie
Rieko
R
Sekiguchi
Satoshi
S
Sakurai
Mikako
M
Sato
Yae
Y
Lee
Won-Woo
WW
Ishii
Yoshiyuki
Y
Kyuwa
Shigeru
S
Noda
Mami
M
Wada
Keiji
K
Yoshikawa
Yasuhiro
Y
D000818:Animals; D015415:Biomarkers; D005434:Flow Cytometry; D015971:Gene Expression Regulation, Enzymologic; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008540:Meiosis / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D018345:Mice, Knockout; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012708:Sertoli Cells / Q000201:enzymology; D013091:Spermatogenesis / Q000502:physiology*; D043222:Ubiquitin Thiolesterase / Q000235:genetics* / Q000378:metabolism*
D015415:Biomarkers; D007527:Isoenzymes; D043222:Ubiquitin Thiolesterase; C496976:Uchl1 protein, mouse