Description
Speract is a decapeptide derived from the outer envelope of the egg; it stimulates motility in spermatozoa. Speract activates its own receptor, a receptor in the scavenger receptor family. Speract increases flagellar Ca2+ levels and increases intracellular Na+, cAMP, and cGMP. Speract also activates K+ channels and alters membrane potential.
References
Guerrero A, Nishigaki T, Carneiro J, et al. Tuning sperm chemotaxis by calcium burst timing. Dev Biol. 2010 Aug 1;344(1):52-65. PMID: 20435032.
Darszon A, Treviño CL, Wood C, et al. Ion channels in sperm motility and capacitation. Soc Reprod Fertil Suppl. 2007;65:229-44. PMID: 17644965.
Wood CD, Nishigaki T, Tatsu Y, et al. Altering the speract-induced ion permeability changes that generate flagellar Ca2+ spikes regulates their kinetics and sea urchin sperm motility. Dev Biol. 2007 Jun 15;306(2):525-37. PMID: 17467684.
Rodríguez E, Darszon A. Intracellular sodium changes during the speract response and the acrosome reaction in sea urchin sperm. J Physiol. 2003 Jan 1;546(Pt 1):89-100. PMID: 12509481.
Cardullo RA, Herrick SB, Peterson MJ, et al. Speract receptors are localized on sea urchin sperm flagella using a fluorescent peptide analog. Dev Biol. 1994 Apr;162(2):600-7. PMID: 8150218.
Babcock DF, Bosma MM, Battaglia DE, et al. Early persistent activation of sperm K+ channels by the egg peptide speract. Proc Natl Acad Sci U S A. 1992 Jul 1;89(13):6001-5. PMID: 1631086.