The dual specificity protein kinase CLK3 is abundantly expressed in mature mouse spermatozoa.
CLK3, a member of the LAMMER family of dual-specificity protein kinases, is abundantly expressed in the reproductive system of male mice. Specifically, high levels of CLK3 protein expression are found in mature spermatozoa in the testis and epididymis. The majority of the CLK3 protein in the testis is a full-length kinase-containing form, and only a small amount of a catalytically inactive N-terminally truncated splice variant protein product is observed. Within the mature spermatozoa CLK3 is localized to the acrosome and tail. CLK3 is expelled from the sperm following the acrosome reaction and inactivated, likely by degradation by the proteases released by the sperm during the acrosome reaction. The CLK family of kinases has previously been implicated in mRNA splicing; however, the bulk of the CLK3 protein in these cells is located in the cytoplasm, suggesting that CLK3 may have additional roles in the cell.
Menegay
H
H
Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.
Moeslein
F
F
Landreth
G
G
D016475:3T3 Cells; D020101:Acrosome Reaction / Q000502:physiology; D000367:Age Factors; D000818:Animals; D000906:Antibodies; D015153:Blotting, Western; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D008297:Male; D051379:Mice; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000235:genetics* / Q000276:immunology; D011505:Protein-Tyrosine Kinases / Q000032:analysis / Q000235:genetics* / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis; D013091:Spermatogenesis / Q000502:physiology*; D013094:Spermatozoa / Q000201:enzymology*; D013737:Testis / Q000166:cytology / Q000201:enzymology; D014158:Transcription, Genetic / Q000502:physiology
D000906:Antibodies; D012333:RNA, Messenger; C066780:Clk dual-specificity kinases; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases