The sperm surface localization of the TRP-3/SPE-41 Ca2+ -permeable channel depends on SPE-38 function in Caenorhabditis elegans

Singaravelu, G, Chatterjee I, Rahimi S, Druzhinina MK, Kang L, Xu XZ, Singson A.  2012.  

Journal:

Dev. Biol.

Volume Number:

365

Pages:

376–383

Abstract:

Despite undergoing normal development and acquiring normal morphology and motility, mutations in spe-38 or trp-3/spe-41 cause identical phenotypes in Caenorhabditis elegans-mutant sperm fail to fertilize oocytes despite direct contact. SPE-38 is a novel, four-pass transmembrane protein and TRP-3/SPE-41 is a Ca(2+)-permeable channel. Localization of both of these proteins is confined to the membranous organelles (MOs) in undifferentiated spermatids. In mature spermatozoa, SPE-38 is localized to the pseudopod and TRP-3/SPE-41 is localized to the whole plasma membrane. Here we show that the dynamic redistribution of TRP-3/SPE-41 from MOs to the plasma membrane is dependent on SPE-38. In spe-38 mutant spermatozoa, TRP-3/SPE-41 is trapped within the MOs and fails to reach the cell surface despite MO fusion with the plasma membrane. Split-ubiquitin yeast-two-hybrid analyses revealed that the cell surface localization of TRP-3/SPE-41 is likely regulated by SPE-38 through a direct protein-protein interaction mechanism. We have identified sequences that influence the physical interaction between SPE-38 and TRP-3/SPE-41, and show that these sequences in SPE-38 are required for fertility in transgenic animals. Despite the mislocalization of TRP-3/SPE-41 in spe-38 mutant spermatozoa, ionomycin or thapsigargin induced influx of Ca(2+) remains unperturbed. This work reveals a new paradigm for the regulated surface localization of a Ca(2+)-permeable channel.

Notes:

[PubMed Central:\href{http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3337337}{PMC3337337}] [DOI:\href{http://dx.doi.org/10.1016/j.ydbio.2012.02.037}{10.1016/j.ydbio.2012.02.037}] [PubMed:\href{http://www.ncbi.nlm.nih.gov/pubmed/22425620}{22425620}]

Citation:
Singaravelu, G, Chatterjee I, Rahimi S, Druzhinina MK, Kang L, Xu XZ, Singson A.  2012.  The sperm surface localization of the TRP-3/SPE-41 Ca2+ -permeable channel depends on SPE-38 function in Caenorhabditis elegans. Dev. Biol.. 365:376–383.