http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:11115 The glioma pathogenesis-related 1 (GLIPR1) family consists of three genes [GLIPR1, GLIPR1-like 1(GLIPR1L1), and GLIPR1-like 2 (GLIPR1L2)] and forms a distinct subgroup within the cysteine-rich secretory protein (CRISP), antigen 5, and pathogenesis-related 1 (CAP) superfamily. CAP superfamily proteins are found in phyla ranging from plants to humans and, based largely on expression and limited functional studies, are hypothesized to have roles in carcinogenesis, immunity, cell adhesion, and male fertility. Specifically data from a number of systems suggests that sequences within the C-terminal CAP domain of CAP proteins have the ability to promote cell-cell adhesion. Herein we cloned mouse Glipr1l1 and have shown it has a testis-enriched expression profile. GLIPR1L1 is posttranslationally modified by N-linked glycosylation during spermatogenesis and ultimately becomes localized to the connecting piece of elongated spermatids and sperm. After sperm capacitation, however, GLIPR1L1 is also localized to the anterior regions of the sperm head. Zona pellucida binding assays indicate that GLIPR1L1 has a role in the binding of sperm to the zona pellucida surrounding the oocyte. These data suggest that, along with other members of the CAP superfamily and several other proteins, GLIPR1L1 is involved in the binding of sperm to the oocyte complex. Collectively these data further strengthen the role of CAP domain-containing proteins in cellular adhesion and propose a mechanism whereby CAP proteins show overlapping functional significance during fertilization. 2012-07-20T03:30:05.808Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:4506 Mammalian spermatozoa must undergo epididymal maturation in the male reproductive tract and capacitation in the female tract before acquiring the ability to fertilize an oocyte. Previous studies from our laboratory have demonstrated a causal relationship between capacitation-associated surface phosphotyrosine expression and the ability of mouse spermatozoa to recognize the oocyte and engage in sperm-zona pellucida interaction. Our previous analyses of the surface phosphoproteome of capacitated murine spermatozoa identified two molecular chaperones, heat shock protein (HSP) D1 and HSP90B1, with well-characterized roles in protein folding and the assemblage of multimeric protein complexes. The expression of these chaperones was restricted to the rostral aspect of the sperm head, in an ideal position to mediate sperm-zona pellucida interaction. Herein, we report the characterization of an additional chaperone in this location, HSPE1 (chaperonin 10; HSP10). This chaperone was identified using a coimmunoprecipitation strategy employing HSPD1 as bait. The putative interaction between HSPE1 and HSPD1 was supported by reciprocal immunoprecipitation and colocalization studies, which demonstrated the coordinated appearance of both proteins on the surface of the sperm head during capacitation. However, the surface exposure of the protein was lost upon induction of acrosomal exocytosis, as would be expected of a protein potentially involved in sperm-zona pellucida interaction. Collectively, these data invite speculation that a number of molecular chaperones are involved in modification of the sperm surface during capacitation to render these cells functionally competent to engage the process of fertilization. 2010-04-27T05:11:26.527Z ]]>