REGULATION OF FLAGELLAR MOTILITY BY TEMPERATURE-DEPENDENT PHOSPHORYLATION OF A 43-KDA AXONEMAL PROTEIN IN FOWL SPERMATOZOA

Phosphorylation of fowl sperm proteins was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) after incubating the demembranated spermatozoa with [γ-32P]ATP at 30°C or 40°C. A marked difference of phosphorylation between 30°C and 40°C was observed in a 43 kDa protein. This protein was slightly phosphorylated at 40°C, but strongly phosphorylated at 30°C in a cAMP-independent manner. The motility of demembranated spermatozoa was negligible at 40°C, but vigorous movement was observed at 30°C. These results showed that phosphorylation of a 43 kDa protein is likely to be a regulatory step in the maintenance of fowl sperm motility. © 1992.