Male infertility-linked point mutation reveals a vital binding role for the C2 domain of sperm PLCζ.
Biochem J
; 474(6): 1003-1016, 2017 03 07.
Article
em En
| MEDLINE
| ID: mdl-28270562
ABSTRACT
Sperm-specific phospholipase C zeta (PLCζ) is widely considered to be the physiological stimulus that evokes intracellular calcium (Ca2+) oscillations that are essential for the initiation of egg activation during mammalian fertilisation. A recent genetic study reported a male infertility case that was directly associated with a point mutation in the PLCζ C2 domain, where an isoleucine residue had been substituted with a phenylalanine (I489F). Here, we have analysed the effect of this mutation on the in vivo Ca2+ oscillation-inducing activity and the in vitro biochemical properties of human PLCζ. Microinjection of cRNA or recombinant protein corresponding to PLCζI489F mutant at physiological concentrations completely failed to cause Ca2+ oscillations and trigger development. However, this infertile phenotype could be effectively rescued by microinjection of relatively high (non-physiological) amounts of recombinant mutant PLCζI489F protein, leading to Ca2+ oscillations and egg activation. Our in vitro biochemical analysis suggested that the PLCζI489F mutant displayed similar enzymatic properties, but dramatically reduced binding to PI(3)P and PI(5)P-containing liposomes compared with wild-type PLCζ. Our findings highlight the importance of PLCζ at fertilisation and the vital role of the C2 domain in PLCζ function, possibly due to its novel binding characteristics.
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Base de dados:
MEDLINE
Assunto principal:
Cálcio
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Mutação Puntual
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Fosfoinositídeo Fosfolipase C
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Domínios C2
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Infertilidade Masculina
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article