Polymorphisms in the human cysteine-rich secretory protein 2 (CRISP2) gene in Australian men.
BACKGROUND
Cysteine-rich secretory protein 2 (CRISP2) is localized to the human sperm acrosome and tail. It can regulate ryanodine receptors Ca(2+) gating and binds to mitogen-activated protein kinase kinase kinase 11 in the acrosome and gametogenetin 1 (GGN1) in the tail.


RESULTS
In order to test the hypothesis that CRISP2 variations contribute to male infertility, we screened coding and flanking intronic regions in 92 infertile men with asthenozoo- and/or teratozoospermia and 176 control men using denaturing HPLC and sequencing. There were 21 polymorphisms identified, including 13 unreported variations. Three SNPs resulted in amino acid substitutions: L59V, M176I and C196R. All were only present in a heterozygous state and found in fertile men. However, the C196R polymorphism was of particular interest as it resulted in the loss of a strictly conserved cysteine involved in intramolecular disulphide bonding. Screening of an additional 637 infertile men identified 23 heterozygous C196R men to give an overall frequency of 3.6%, compared with 3.4% in control men. The functional significance of the C196R polymorphism was defined using a yeast two-hybrid assay. The C196R substitution resulted in the loss of CRISP2-GGN1 binding.


CONCLUSIONS
Although none of the many polymorphisms identified herein showed a significant association with male infertility, functional studies suggested that the C196R polymorphism may compromise CRISP2 function.
Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, Clayton, VIC, Australia.
D
D
Jamsai
A
A
Reilly
S J
SJ
Smith
G M
GM
Gibbs
H W G
HW
Baker
R I
RI
McLachlan
D M
DM
de Kretser
M K
MK
O'Bryan
D019943:Amino Acid Substitution; D001315:Australia; D016022:Case-Control Studies; D015815:Cell Adhesion Molecules; D002851:Chromatography, High Pressure Liquid; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D006579:Heterozygote; D006801:Humans; D007248:Infertility, Male / Q000235:genetics*; D008297:Male; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D013737:Testis / Q000378:metabolism
C062621:CRISP2 protein, human; D015815:Cell Adhesion Molecules; D006023:Glycoproteins