title: Dephosphorylation of a 30-kDa protein of fowl spermatozoa by the addition of myosin light chain kinase substrate peptide inhibits the flagellar motility.
abstract: Phosphorylation of demembranated fowl sperm proteins during incubation with [gamma-32P]ATP and various protein kinase substrate peptides at 30 degrees C was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). A marked difference in phosphorylation was observed in a 30 kDa protein. This protein was strongly phosphorylated after the addition of Kemptide, a cAMP-dependent protein kinase (PKA) substrate peptide; Syntide 2, a calmodulin-dependent protein kinase II substrate peptide; a protein kinase C (PKC) substrate peptide; as well as control samples but only slightly phosphorylated in the presence of a myosin light chain kinase (MLCK) substrate peptide. The motility of demembranated spermatozoa at 30 degrees C remained high in control samples and following the addition of Kemptide, Syntide 2 and PKC substrate peptide, but decreased markedly following the addition of MLCK substrate peptide. These results suggest that the 30 kDa protein is identified as a substrate for MLCK or a MLCK-like protein in fowl spermatozoa and that phosphorylation-dephosphorylation of this protein is involved in the regulation of flagellar movement at 30 degrees C.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D002645:Chickens; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism / Q000494:pharmacology*; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D013081:Sperm Motility / Q000187:drug effects*; D013082:Sperm Tail / Q000187:drug effects / Q000502:physiology*; D013094:Spermatozoa / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D013379:Substrate Specificity
chemical_list: D009842:Oligopeptides; D010750:Phosphoproteins; D000255:Adenosine Triphosphate; D011494:Protein Kinases; D009219:Myosin-Light-Chain Kinase