Egg fucose sulfate polymer,sialoglycan, and speract all trigger the sea urchin sperm acrosome reaction |
| |
Authors: | Hirohashi Noritaka Vacquier Victor D |
| |
Affiliation: | Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California-San Diego, La Jolla, CA 92093-0202, USA. nhirohashi@ucsd.edu |
| |
Abstract: | Macromolecules surrounding eggs induce the acrosome reaction (AR) of spermatozoa. In sea urchins, three egg jelly (EJ) molecules: a fucose sulfate polymer (FSP), a sialoglycan (SG), and speract mediate ionic fluxes triggering the AR. SG and speract are noninductive without FSP. Speract's role in AR induction is controversial. Here we show that speract potentiates the FSP-induced AR at pH 7.0, approximately 1 pH unit lower than natural seawater. At pH 7.0, a mixture of FSP, SG, and speract produces the intracellular pH increase necessary for maximum AR induction. Each EJ component may mediate a distinct intracellular pH control mechanism, and all three may function synergistically to increase the intracellular pH permitting AR induction. Speract peptides are an ancient family. Although important for activating cyclic nucleotide-mediated pathways in today's seawater of pH approximately 8, speract may have been more important in AR induction in the paleo-ocean of pH approximately 7. |
| |
Keywords: | Fertilization Sperm ion flux Intracellular pH Sperm-egg interaction Acrosome reaction Egg jelly Speract Polysialic acid Sea urchin Paleo-ocean |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|