title: Aquaporin inhibition changes protein phosphorylation pattern following sperm motility activation in fish.
abstract: Our previous studies demonstrated that osmolality is the key signal in sperm motility activation in Sparus aurata spermatozoa. In particular, we have proposed that the hyper-osmotic shock triggers water efflux from spermatozoa via aquaporins. This water efflux determines the cell volume reduction and, in turn, the rise in the intracellular concentration of ions. This increase could lead to the activation of adenylyl cyclase and of the cAMP-signaling pathway, causing the phosphorylation of sperm proteins and then the initiation of sperm motility. This study confirms the important role of sea bream AQPs (Aqp1a and Aqp10b) in the beginning of sperm motility. In fact, when these proteins are inhibited by HgCl(2), the phosphorylation of some proteins (174 kDa protein of head; 147, 97 and 33 kDa proteins of flagella), following the hyper-osmotic shock, was inhibited (totally or partially). However, our results also suggest that more than one transduction pathways could be activated when sea bream spermatozoa were ejaculated in seawater, since numerous proteins showed an HgCl(2)(AQPs)-independent phosphorylation state after motility activation. The role played by each different signal transduction pathways need to be clarified.
authors.affiliation: Department of Biological and Environmental Sciences and Technologies, University of Salento, Lecce, Italy. loredana.zilli@unisalento.it
authors.forename: Loredana
authors.initials: L
authors.lastname: Zilli
authors.forename: José
authors.initials: J
authors.lastname: Beirão
authors.forename: Roberta
authors.initials: R
authors.lastname: Schiavone
authors.forename: Maria Paz
authors.initials: MP
authors.lastname: Herraez
authors.forename: Elsa
authors.initials: E
authors.lastname: Cabrita
authors.forename: Carlo
authors.initials: C
authors.lastname: Storelli
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Vilella
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D020346:Aquaporins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D005407:Flagella / Q000187:drug effects / Q000502:physiology; D008297:Male; D008627:Mercuric Chloride / Q000494:pharmacology; D009994:Osmolar Concentration; D010766:Phosphorylation / Q000187:drug effects; D021541:Sea Bream / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism*; D014741:Video Recording
chemical_list: D020346:Aquaporins; D008627:Mercuric Chloride; D000262:Adenylyl Cyclases