Regulation of sperm motility: emerging evidence for a major role for protein phosphatases.

Lesions in the normal expression of sperm motility are associated with certain types of male infertility. Therefore, an understanding of the signal transduction pathways regulating sperm motility will be an important part of our understanding of the mechanisms underlying these types of male infertility. In this connection, the regulation of sperm fiagellar motility by second messengers is a rapidly expanding area of research in cell and reproductive biology. While abundant information can be found concerning protein kinases and phosphoproteins in relation to sperm motility, relatively little attention has been paid to the potential role for protein phosphatases in this process. This review will focus attention on protein phosphatases, in the context of current literature and more recent studies, as a growing area of interest in relation to the role that protein phosphorylation plays in the regulation of motility of sperm and other axoneme-containing cells.