Identification of Three Isoforms for the Na+-dependent Phosphate Cotransporter (NaPi-2) in Rat Kidney*
Identification of Three Isoforms for the Na+-dependent Phosphate Cotransporter (NaPi-2) in Rat Kidney*
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大鼠肾脏中 Na 依赖性磷酸盐协同转运蛋白 (NaPi-2) 的三种亚型的鉴定*
DOI：
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发表时间：
1998
影响因子：
4.8
通讯作者：
E. Takeda
中科院分区：
文献类型：
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作者：
S. Tatsumi;K. Miyamoto;T. Kouda;Keiko Motonaga;K. Katai;I. Ohkido;K. Morita;H. Segawa;Yoshiko Tani;Hironori Yamamoto;Y. Taketani;E. Takeda
我们从大鼠肾脏文库中分离了三个独特的NaPi-2相关蛋白cDNA（NaPi-2α、NaPi-2β和NaPi-2γ）。NaPi-2α cDNA编码337个氨基酸，与含有3个跨膜结构域的NaPi-2的N-末端有很高的同源性。NaPi-2β编码327个氨基酸，与含有4个跨膜结构域的NaPi-2的N-末端区域相同，而C-末端区域中的146个氨基酸完全不同。相比之下，NaPi-2γ编码268个氨基酸，其与NaPi-2的C-末端一半相同。噬菌体和粘粒克隆的分析表明，这三个相关的蛋白质产生的选择性剪接的NaPi-2基因。在兔网织红细胞裂解物系统中，发现NaPi-2 α、β和γ分别为36、36和29 kDa氨基酸多肽。NaPi-2α和NaPi-2γ被糖基化，分别为45和35 kDa蛋白。在分离的刷状缘膜囊泡中，N-末端抗体与45-和40-kDa反应，C-末端抗体与37-kDa蛋白反应。这些蛋白质的大小对应于糖基化形式的那些。功能分析表明，NaPi-2γ和NaPi-2 α对爪蟾卵母细胞的NaPi-2活性有明显的抑制作用。结果表明，这些短的异构体可能作为一个显性负抑制剂的全长转运。
We have isolated three unique NaPi-2-related protein cDNAs (NaPi-2α, NaPi-2β, and NaPi-2γ) from a rat kidney library. NaPi-2α cDNA encodes 337 amino acids which have high homology to the N-terminal half of NaPi-2 containing 3 transmembrane domains. NaPi-2β encodes 327 amino acids which are identical to the N-terminal region of NaPi-2 containing 4 transmembrane domains, whereas the 146 amino acids in the C-terminal region are completely different. In contrast, NaPi-2γ encodes 268 amino acids which are identical to the C-terminal half of NaPi-2. An analysis of phage and cosmid clones indicated that the three related proteins were produced by alternative splicing in the NaPi-2 gene. In a rabbit reticulocyte lysate system, NaPi-2 α, β, and γ were found to be 36, 36, and 29 kDa amino acid polypeptides, respectively. NaPi-2α and NaPi-2γ were glycosylated and revealed to be 45- and 35-kDa proteins, respectively. In isolated brush-border membrane vesicles, an N-terminal antibody was reacted with 45- and 40-kDa, and a C-terminal antibody was reacted with 37-kDa protein. The sizes of these proteins corresponded to those in glycosylated forms. A functional analysis demonstrated that NaPi-2γ and -2α markedly inhibited NaPi-2 activity in Xenopus oocytes. The results suggest that these short isoforms may function as a dominant negative inhibitor of the full-length transporter.
大鼠肾皮质中 Na/Pi 共转运编码 mRNA 响应低 Pi 饮食而增加。
DOI：
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发表时间：
1994
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Werner,A;Kempson,SA;Biber,J;Murer,H
通讯作者：
Murer,H
影响因子：
19.6
作者：
Kavanaugh, MP;Kabat, D
通讯作者：
Kabat, D