Characterization of a 25 kDa sperm-perinuclear theca protein.

摘要

The perinuclear theca (PT) is a rigid cytoskeletal structure that underlies the acrosome and envelopes the sperm-nucleus on all sides, except for a small area on the basal side of the nucleus where the tail inserts. The PT is implicated in a number of cellular functions such as acrosome formation, sperm-nucleus reshaping during spermiogenesis and egg activation during fertilization. This highly insoluble structure contains several proteins in relatively high abundance. Identification of these proteins is critical to understanding PT function. One prominent PT protein is the 25-kDa, SDS non-extractable protein (PT25). Our objectives were to characterize the sequence and developmental expression of PT25. This information could increase our understanding of the PT and identify potential roles for this protein. Rab proteins are involved in many stages of vesicular transport, and are regarded as master regulators of this important cellular process. Using both matrix-assisted laser-desorption ionization time-of-flight (MALDI-TOF) MS and quadrupole time-of-flight (Q-TOF) MS. 72% of the sequence of Rab2 has been matched to fragments of PT25. (Abstract shortened by UMI.).