Guanylate-cyclase-inhibitory protein is a frog retinal Ca2+-binding protein related to mammalian guanylate-cyclase-activating proteins.
Guanylate-cyclase-inhibitory protein is a frog retinal Ca2+-binding protein related to mammalian guanylate-cyclase-activating proteins.
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鸟苷酸环化酶抑制蛋白是与哺乳动物鸟苷酸环化酶激活蛋白相关的青蛙视网膜 Ca2 结合蛋白。
DOI：
10.1046/j.1432-1327.1998.2520591.x
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Baehr,W
中科院分区：
文献类型：
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作者：
Li,N;Fariss,RN;Zhang,K;Otto-Bruc,A;Haeseleer,F;Bronson,D;Qin,N;Yamazaki,A;Subbaraya,I;Milam,AH;Palczewski,K;Baehr,W
两种鸟苷酸环化酶激活蛋白（GCAP）由尾对尾基因阵列编码，在哺乳动物视网膜中被表征。使用青蛙视网膜作为模型，我们获得了与GCAP密切相关的光感受器Ca2+结合蛋白存在的证据。该蛋白（206个氨基酸）在低[Ca2+]条件下不刺激鸟苷酸环化酶（GC），但在高[Ca2+]条件下抑制GC，因此被称为鸟苷酸环化酶抑制蛋白（GCIP）。序列分析表明GCIP与GCAP1和GCAP2存在较大的差异，但在所有脊椎动物中都存在GCAP的保守结构域。此外，对GCIP基因的部分表征表明，GCIP基因中两个内含子的位置与哺乳动物GCAP基因阵列中相应内含子的位置相同。至于GCIP和GCAP之间的主要区别，GCIP的第四个EF手Ca2+结合基序被Ca2+结合禁用，并且GCIP不刺激GC。重组GCIP单克隆和多克隆抗体在蛙视锥细胞内段、体细胞和突触末端发现了高水平的GCIP。结果表明，GCIP是GCAP/recoverin亚家族的Ca2+结合蛋白。它在青蛙视锥细胞中的定位与哺乳动物视锥细胞中的定位非常相似。GCIP以高游离[Ca2+]抑制GC，与GCAP1和GCAP2竞争GC调控位点。
Two guanylate‐cyclase‐activating proteins (GCAP) encoded by a tail‐to‐tail gene array have been characterized in the mammalian retina. Using frog retina as a model, we obtained evidence for the presence of a photoreceptor Ca2+‐binding protein closely related to GCAP. This protein (206 amino acids) does not stimulate guanylate cyclase (GC) in low [Ca2+], but inhibits GC in high [Ca2+], and is therefore termed guanylate‐cyclase‐inhibitory protein (GCIP). Sequence analysis indicates that GCIP and GCAP1 and GCAP2 have diverged substantially, but conserved domains present in all vertebrate GCAP are present in GCIP. Moreover, partial characterization of the GCIP gene showed that the positions of two introns in the GCIP gene are identical to positions of corresponding introns of the mammalian GCAP gene array. As to the major differences between GCIP and GCAP, the fourth EF hand Ca2+‐binding motif of GCIP is disabled for Ca2+binding, and GCIP does not stimulate GC. Monoclonal and polyclonal antibodies raised against recombinant GCIP identified high levels of GCIP in the inner segments, somata and synaptic terminals of frog cone photoreceptors. The results suggest that GCIP is a Ca2+‐binding protein of the GCAP/recoverin subfamily. Its localization in frog cones closely resembles that of GC in mammalian cones. GCIP inhibits GC at high free [Ca2+], competing with GCAP1 and GCAP2 for GC regulatory sites.