title: Functional disparity between human PAWP and PLCζ in the generation of Ca2+ oscillations for oocyte activation.
abstract: Mammalian oocyte activation is mediated by cytosolic calcium (Ca(2+)) oscillations initiated upon delivery of a putative 'sperm factor' by the fertilizing sperm. Previous studies suggest the identity of this sperm factor as the testis-specific phospholipase C-zeta (PLCζ). Recently, a post-acrosomal sheath WW domain-binding protein (PAWP) has been proposed as an alternative sperm factor candidate, following a report that human PAWP protein and cRNA elicited Ca(2+) oscillations in mouse and human oocytes. Those Ca(2+) oscillations were inhibited by a PAWP-derived peptide corresponding to a functional PPGY binding motif. Herein, using a series of human PAWP expression constructs, we demonstrate that both human PAWP protein and cRNA are, in our experiments, unable to elicit Ca(2+) release following microinjection into mouse oocytes. Parallel experiments performed with human PLCζ elicited the characteristic Ca(2+) oscillations present at mammalian fertilization, which produced oocyte activation and embryo development. Furthermore, sperm-induced Ca(2+) oscillations were not inhibited by the PAWP-derived PPGY peptide following in vitro fertilization or intracytoplasmic sperm injection. Thus, the functional disparity with PLCζ leads us to conclude that human PAWP is neither sufficient nor necessary for the Ca(2+) oscillations that initiate mammalian oocyte activation at fertilization.
authors.affiliation: Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK lait@cf.ac.uk mixosn@yahoo.com.
authors.forename: Michail
authors.initials: M
authors.lastname: Nomikos
authors.affiliation: Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK.
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Sanders
authors.affiliation: Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK College of Medicine, Alfaisal University, Riyadh, Kingdom of Saudi Arabia Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Junaid
authors.initials: J
authors.lastname: Kashir
authors.affiliation: Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK.
authors.forename: Randa
authors.initials: R
authors.lastname: Sanusi
authors.affiliation: Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK.
authors.forename: Luke
authors.initials: L
authors.lastname: Buntwal
authors.affiliation: Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Love
authors.affiliation: Wales Fertility Institute, University Hospital of Wales, Cardiff CF14 4XW, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Ashley
authors.affiliation: Wales Fertility Institute, University Hospital of Wales, Cardiff CF14 4XW, UK.
authors.forename: David
authors.initials: D
authors.lastname: Sanders
authors.affiliation: Wales Fertility Institute, University Hospital of Wales, Cardiff CF14 4XW, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Knaggs
authors.affiliation: Wales Fertility Institute, University Hospital of Wales, Cardiff CF14 4XW, UK.
authors.forename: Adnan
authors.initials: A
authors.lastname: Bunkheila
authors.affiliation: Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK.
authors.forename: Karl
authors.initials: K
authors.lastname: Swann
authors.affiliation: Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK lait@cf.ac.uk mixosn@yahoo.com.
authors.forename: F Anthony
authors.initials: FA
authors.lastname: Lai
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D005260:Female; D005307:Fertilization in Vitro; D018014:Gene Transfer Techniques; D006801:Humans; D059471:In Vitro Oocyte Maturation Techniques; D008297:Male; D051379:Mice; D008845:Microinjections; D009865:Oocytes / Q000187:drug effects / Q000201:enzymology*; D010446:Peptide Fragments / Q000494:pharmacology; D054801:Phosphoinositide Phospholipase C / Q000235:genetics / Q000378:metabolism*; D029589:Seminal Plasma Proteins / Q000235:genetics / Q000378:metabolism*; D020554:Sperm Injections, Intracytoplasmic; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000378:metabolism; D013997:Time Factors
chemical_list: D002352:Carrier Proteins; D010446:Peptide Fragments; D029589:Seminal Plasma Proteins; C519840:WBP2NL protein, human; C499235:PLCZ1 protein, human; D054801:Phosphoinositide Phospholipase C
keywords: PAWP; fertilization; oocyte activation; phospholipase C zeta; sperm factor