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This Article Full Text Full Text (PDF) [Supplemental Table 1] All Versions of this Article: 79/1/75    most recent biolreprod.107.066308v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Zhang, Z. Articles by Strauss, J. F Search for Related Content PubMed PubMed Citation Articles by Zhang, Z. Articles by Strauss, J. F, III Agricola Articles by Zhang, Z. Articles by Strauss, J. F

Phosphorylation of Mouse Sperm Axoneme Central Apparatus Protein SPAG16L by a Testis-Specific Kinase, TSSK2¹

Department of Obstetrics & Gynecology,³ Virginia Commonwealth University, Richmond, Virginia 23298 Center for Research on Reproduction and Women's Health,⁴ University of Pennsylvania, Philadelphia, Pennsylvania 19104 Department of Cell Biology,⁵ University of Virginia Medical School, Charlottesville, Virginia 22908

ABSTRACT

The mammalian protein SPAG16L, the ortholog of Chlamydomonas Pf20, is an axoneme central apparatus protein necessary for flagellar motility. The SPAG16L protein sequence contains multiple potential phosphorylation sites, and the protein was confirmed to be phosphorylated in vivo. A yeast two-hybrid screen identified the testis-specific kinase, TSSK2, to be a potential SPAG16L binding partner. SPAG16L and TSSK2 interactions were confirmed by coimmunoprecipitation of both proteins from testis extracts and cell lysates expressing these proteins, and their colocalization was also noted by confocal microscopy in Chinese hamster ovary cells, where they were coexpressed. TSSK2 associates with SPAG16L via its C-terminal domain bearing WD repeats. The N-terminal domain containing a coiled coil motif does not associate with TSSK2. SPAG16L can be phosphorylated by TSSK2 in vitro. Finally, TSSK2 is absent or markedly reduced from the testes in most of the SPAG16L-null mice. These data support the conclusion that SPAG16L is a TSSK2 substrate.

kinase, phosphorylation, SPAG16L, sperm motility

¹Supported by National Institutes of Health grants HD37416, HD06724, and TW06223-01.

Correspondence: ²Zhibing Zhang, Department of Obstetrics & Gynecology, Virginia Commonwealth University, 11028A Sanger Hall, 1101 East Marshall St., Richmond, VA 23298. FAX: 804 828 0573; e-mail: zzhang4{at}vcu.edu