标题: Blood pressure and fertility [打印本页] 作者: 杨柳 时间: 2009-3-6 08:53 标题: Blood pressure and fertility
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A target of blood pressure–lowering drugs harbors the unexpected ability to release GPI-anchored proteins. Gen Kondoh (Kyoto University, Kyoto, Japan), Junji Takeda (Osaka University, Osaka, Japan), and colleagues reveal that this enzyme, ACE, is both a peptidase and GPIase in one multifunctional package.ACE's peptidase activity is well studied〞it cleaves and activates angiotensin, which up-regulates blood pressure through hormonal changes. But Kondoh did not expect to find ACE in his screen for proteins that release GPI-anchored proteins from the cell surface.# M$ Z, R4 G5 ]% H# C2 C
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GPI deficiencies cause severe problems in fertility and development. GPI also links the prion protein to membranes. But the activities that release these linkages were not well-known. Now, Kondoh shows that a region of ACE distinct from its peptidase domain has this ability. Soluble prion protein protects against scrapie, so ACE, especially a peptidase-inactive form, may be a useful disease treatment. % G% u2 ?3 a: _0 y( F2 M! n0 I- }& ?$ P! ~5 K' a% X! j: z
As ACE was found in a mouse testicular preparation, the group examined sperm lacking the ACE GPIase activity. The mutant sperm were infertile and unable to release several GPI-linked proteins from their surface.% K0 O% H0 \/ T& K
/ N+ l \; T9 t8 H4 ?; J$ RAnchored proteins were partly protected from ACE cleavage if they were in lipid rafts. By keeping GPI-linked fertilization factors in rafts, their release could be delayed until the raft disruption that occurs during capacitation.0 C8 n" x% ~ Y) ~$ N4 _/ d# C7 c
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Reference: $ r1 A- q& y7 r0 [7 W 5 S, a% J4 J. m# XKondoh, G., et al. 2005. Nat. Med. doi:10.1038/nm1179(Sperm–egg binding (left) is lost when AC)作者: branch2 时间: 2009-12-6 17:01
As ACE was found in a mouse testicular preparation, the group examined sperm lacking the ACE GPIase activity. The mutant sperm were infertile and unable to release several GPI-linked proteins from their surface.* \. A/ i" |/ C
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