Structure and function of epididymal protein cysteine-rich secretory protein-1.
- Author:
Kenneth P ROBERTS
1
;
Daniel S JOHNSTON
;
Michael A NOLAN
;
Joseph L WOOTERS
;
Nicole C WAXMONSKY
;
Laura B PIEHL
;
Kathy M ENSRUD-BOWLIN
;
David W HAMILTON
Author Information
1. Department of Urologic Surgery, University of Minnesota, MMC 394, 420 Delaware Street SE, Minneapolis, MN 55455, USA. rober040@umn.edu
- Publication Type:Journal Article
- MeSH:
Amino Acid Sequence;
Animals;
Conserved Sequence;
Humans;
Male;
Mammals;
Membrane Glycoproteins;
genetics;
metabolism;
Molecular Sequence Data;
Rats;
Spermatozoa;
physiology
- From:
Asian Journal of Andrology
2007;9(4):508-514
- CountryChina
- Language:English
-
Abstract:
Cysteine-rich secretory protein-1 (CRISP-1) is a glycoprotein secreted by the epididymal epithelium. It is a member of a large family of proteins characterized by two conserved domains and a set of 16 conserved cysteine residues. In mammals, CRISP-1 inhibits sperm-egg fusion and can suppress sperm capacitation. The molecular mechanism of action of the mammalian CRISP proteins remains unknown, but certain non-mammalian CRISP proteins can block ion channels. In the rat, CRISP-1 comprises two forms referred to as Proteins D and E. Recent work in our laboratory demonstrates that the D form of CRISP-1 associates transiently with the sperm surface, whereas the E form binds tightly. When the spermatozoa are washed, the E form of CRISP-1 persists on the sperm surface after all D form has dissociated. Cross-linking studies demonstrate different protein-protein interaction patterns for D and E, although no binding partners for either protein have yet been identified. Mass spectrometric analyses revealed a potential post-translational modification on the E form that is not present on the D form. This is the only discernable difference between Proteins D and E, and presumably is responsible for the difference in behavior of these two forms of rat CRISP-1. These studies demonstrate that the more abundant D form interacts with spermatozoa transiently, possibly with a specific receptor on the sperm surface, consistent with a capacitation-suppressing function during sperm transit and storage in the epididymis, and also confirm a tightly bound population of the E form that could act in the female reproductive tract.
