« Previous Abstract"Gene identification and evidence for expression of G protein alpha subunits, phospholipase C, and an inositol 1,4,5-trisphosphate receptor in Aplysia californica rhinophore"    Next AbstractCandidate chemoreceptor subfamilies differentially expressed in the chemosensory organs of the mollusc Aplysia »

Peptides

Title:		"Characterization of Aplysia Alb-1, a candidate water-borne protein pheromone released during egg laying"
Author(s):		Cummins SF; Degnan BM; Nagle GT;
Address:		"Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555-0620, USA. s.cummins@uq.edu.au"
Journal Title:		Peptides
Year:		2008
Volume:		20071205
Issue:		2
Page Number:		152 - 161
DOI:		10.1016/j.peptides.2007.07.031
ISSN/ISBN:		0196-9781 (Print) 0196-9781 (Linking)
Abstract:		"Pheromones are known to be important to the innate behavior of marine animals. Attraction in Aplysia involves the long-distance water-borne protein pheromones attractin, enticin, temptin and seductin, which are released from the albumen gland during egg laying. Other pheromones are predicted to act in concert with these pheromones, but their identities are unknown. To identify additional pheromone candidates, we employed differential library screening of an albumen gland cDNA library, RT-PCR, recombinant protein expression, rhinophore contraction bioassays and immunocytochemistry. Alb-1 is expressed in the Aplysia californica albumen gland and encodes a novel protein that does not share significant sequence identity with any proteins in the database. RT-PCR analysis detected Alb-1 transcripts in the albumen gland, exocrine atrial gland and ovotestis. The Alb-1 precursor has a signal peptide sequence followed by a predicted 101-residue protein sequence containing eight cysteine residues. Recombinant protein expression, RP-HPLC, microsequence analysis and MALDI mass spectrometry analyses demonstrated that mature recombinant Alb-1 was processed at a paired basic residue site to generate an N-terminal and C-terminal protein fragment; this was consistent with immunoblot observations on purified albumen gland extracts. In rhinophore contraction (twitch) bioassays, the recombinant N-terminal protein induced rhinophore contractions whereas the C-terminal protein did not. An antibody generated to the N-terminal protein was used for immunocytochemical and immunoblot analyses and demonstrated that this protein is present in albumen gland secretory cells, egg cordons and egg eluates. Overall, the data suggest that Alb-1 may be processed in the albumen gland and that the Alb-1 1-56 protein released during egg laying may serve a pheromonal function in concert with attractin, enticin, temptin and seductin"
Keywords:		"Amino Acid Sequence Animals Aplysia/*genetics/metabolism Cloning, Molecular Exocrine Glands/chemistry/metabolism Gene Expression *Gene Library Gonads/chemistry/metabolism Molecular Sequence Data Muscle Contraction/drug effects Pheromones/*genetics/metabol;"
Notes:		"MedlineCummins, Scott F Degnan, Bernard M Nagle, Gregg T eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2008/01/15 Peptides. 2008 Feb; 29(2):152-61. doi: 10.1016/j.peptides.2007.07.031. Epub 2007 Dec 5"