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.
Jamsai
D
D
Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, Clayton, VIC, Australia.
Reilly
A
A
Smith
S J
SJ
Gibbs
G M
GM
Baker
H W G
HW
McLachlan
R I
RI
de Kretser
D M
DM
O'Bryan
M K
MK
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