Platelet-Activating Factor Acetylhydrolase and Brain Development.

The heterotrimeric brain platelet-activating factor acetylhydrolase (PAFAH1B1) contains two catalytic subunits and a regulatory subunit. This complex plays important, surprising roles in brain development and in spermatogenesis. The regulatory subunit, PAFAH1B1 (LIS1 protein), is critically regulated and when deficient leads to the devastating human neurological disorder Lissencephaly, or smooth brain. The role of the protein in brain development is not the catalysis of platelet-activating factor, rather the entire brain platelet-activating factor acetylhydrolase complex serves a signaling role, coordinating important pathways in brain development. The role of this complex in spermatogenesis was not foreseen, but appears to function to regulate a critical level of the PAFAH1B1 protein, such that too much of this protein or too little of this protein can lead to a disruption of spermatogenesis. Brain platelet-activating factor is thus a signaling complex, important for brain development and for spermatogenesis.