Ohta K, Sato C, Matsuda T, Toriyama M, Vacquier VD, Lennarz WJ, Kitajima K. Co-localization of receptor and transducer proteins in the glycosphingolipid-enriched, low density, detergent-insoluble membrane fraction of sea urchin sperm.
Glycoconj J 2000;
17:205-14. [PMID:
11201792 DOI:
10.1023/a:1026589223811]
[Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The low density, detergent-insoluble membrane fraction (LD-DIM), where gangliosides are likely to be highly enriched, was prepared from sperm of two sea urchin species, Hemicentrotus pulcherrimus and Strongylocentrotus purpuratus. Immunoblotting showed the presence in the LD-DIM of two receptors for egg ligands, a glycosylphosphatidylinositol (GPI)-anchored protein, and four proteins which may be involved in signal transduction. Co-immunoprecipitation revealed that at least three proteins, the speract receptor, the 63kDa GPI-anchored protein and the alpha subunit of a heterotrimeric Gs protein, are localized in the LD-DIM. This suggests that the LD-DIM fraction may be a membrane microdomain for speract-speract receptor interaction, as well as the subsequent signal transduction pathway involved in induction of sperm respiration, motility and possibly the acrosome reaction.
Collapse