|
|
Copyright © 2001 by the National Academy of Sciences.
Allurin, a 21-kDa sperm chemoattractant from Xenopus egg jelly, is related to mammalian sperm-binding proteins
John H. Olson*,
Xueyu Xiang*,
Tillmann Ziegert,
Andrew Kittelson,
Alan Rawls,
Allan L. Bieber, and
Douglas E. Chandler Molecular and Cellular Biology Program and the Departments of Biology and Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1501 Received for publication June 22, 2001.Abstract: Previously, we demonstrated that a protein from Xenopus egg jelly exhibits sperm chemoattractant activity when assayed by either video microscopy or by sperm passage across a porous filter. Here we describe the isolation and purification of allurin, the protein responsible for this activity. Freshly oviposited jellied eggs were soaked in buffer, and the conditioned medium was loaded onto an anion exchange column and eluted with an NaCl gradient. The active fraction was purified further by RP-HPLC, the chemoattractant protein appearing as a single sharp peak. The amino acid sequence of the protein, determined by direct sequencing and cloning of cDNAs coding for the protein, consisted of 184 amino acids having a molecular mass of 21,073 Da. The protein shares homology with the mammalian cysteine-rich secretory protein (CRISP) family that includes testes-specific spermatocyte protein 1, a cell adhesion protein which links spermatocytes to Seritoli cells, and acidic epididymal glycoproteins that bind to sperm and have been implicated in sperm–egg fusion. Phylogenetic analysis suggests that allurin evolved from the ancestral protein that gave rise to the mammalian CRISP family. Addition of allurin to this family portends that the CRISP family represents a group of "sperm escort" proteins, which bind to sperm at various steps in their life history, facilitating passage from one functional stage to the next. Allurin stands out in this regard, representing both the first vertebrate sperm chemoattractant to be purified and sequenced and the first member of the CRISP family to be found in the female reproductive tract.
Key Words: sperm chemotaxis • fertilization • TPX-1 • AEG • CRISP
* J.H.O. and X.X. contributed equally to this work.
Edited by William J. Lennarz, State University of New York, Stony Brook, NY, and approved August 10, 2001 This paper was submitted directly (Track II) to the PNAS office. Data deposition: The sequence reported in this paper has been deposited in the GenBank database (accession no. AF393653).
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
|
To whom reprint requests should be addressed at: Department of Biology, Arizona State University, P.O. Box 871501, Tempe, AZ 85287-1501. E-mail: Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882
News | Science Journals | Careers | Blogs and Communities | Multimedia | Collections | Help | Site Map | RSS
Subscribe | Feedback | Privacy / Legal | About Us | Advertise With Us | Contact Us
© 2001 American Association for the Advancement of Science. All Rights Reserved.
AAAS is a partner of HINARI, AGORA, OARE, PatientInform, CrossRef, and COUNTER.
You have reached the bottom of the page. Back to top