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Identification of mouse trp homologs and lipid rafts from spermatogenic cells and sperm
Author(s) -
Treviño Claudia L.,
Serrano Carmen J.,
Beltrán Carmen,
Felix Ricardo,
Darszon Alberto
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)03134-9
Subject(s) - lipid raft , sperm , microbiology and biotechnology , capacitation , caveolae , biology , ganglioside , acrosome , cholera toxin , flagellum , sperm motility , motility , signal transduction , biochemistry , genetics , gene , endocrinology
Intracellular Ca 2+ has an important regulatory role in the control of sperm motility, capacitation, and the acrosome reaction (AR). However, little is known about the molecular identity of the membrane systems that regulate Ca 2+ in sperm. In this report, we provide evidence for the expression of seven Drosophila transient receptor potential homolog genes ( trp 1–7) and three of their protein products ( Trp 1, Trp 3 and Trp 6) in mouse sperm. Allegedly some trp s encode capacitative Ca 2+ channels. Immunoconfocal images showed that while Trp 6 was present in the postacrosomal region and could be involved in sperm AR, expression of Trp 1 and Trp 3 was confined to the flagellum, suggesting that they may serve sperm to regulate important Ca 2+ ‐dependent events in addition to the AR. Likewise, one of these proteins ( Trp 1) co‐immunolocalized with caveolin‐1, a major component of caveolae, a subset of lipid rafts potentially important for signaling events and Ca 2+ flux. Furthermore, by using fluorescein‐coupled cholera toxin B subunit, which specifically binds to the raft component ganglioside GM1, we identified caveolin‐ and Trp ‐independent lipid rafts residing in the plasma membrane of mature sperm. Notably, the distribution of GM1 changes drastically upon completion of the AR.