Distinct distribution of specific members of protein 4.1 gene family in the mouse nephron
Distinct distribution of specific members of protein 4.1 gene family in the mouse nephron
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DOI：
10.1046/j.1523-1755.2003.00870.x
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发表时间：
2003-04-01
影响因子：
19.6
通讯作者：
Gascard, P
中科院分区：
文献类型：
--
作者：
Ramez, M;Blot-Chabaud, M;Gascard, P
背景蛋白4.1是连接肌动蛋白细胞骨架与各种跨膜蛋白的衔接蛋白。这些4.1蛋白由4个同源基因4.1R、4.1G、4.1N和4.1B编码，它们经历复杂的选择性剪接。在这里，我们进行了详细的表征的表达的特定4.1蛋白在小鼠肾单位。通过用对每种4.1蛋白具有高度特异性的抗体对多聚甲醛固定的小鼠肾切片进行染色，研究肾4.1蛋白的分布。从小鼠肾脏马拉松cDNA中扩增的主要4.1剪接形式在转染的COS-7细胞中表达，以将已知外显子组成的物种分配给肾脏中检测到的蛋白质。一个105 kD的4.1R剪接形式，起始于ATG-2翻译起始位点，缺乏外显子16，但包括外显子17 B，仅限于Henle环的粗升支。一个95 kD的4.1N剪接形式，缺乏外显子15和17 D，表达在亨利氏袢，远曲小管，和集合管系统的所有区域的下降或上升的薄肢。一个主要的108 kD的4.1B剪接形式，开始在一个新的特征ATG翻译起始位点，并缺乏外显子15，17 B和21，是目前只在鲍曼氏囊和近曲小管（PCT）。肾组织中未见4.1G蛋白表达。4.1蛋白沿着肾单位的独特分布表明它们参与靶向肾上皮中的选定跨膜蛋白，因此参与特定肾功能的调节。
Background. Protein 4.1 is an adapter protein that links the actin cytoskeleton to various transmembrane proteins. These 4.1 proteins are encoded by four homologous genes, 4.1R, 4.1G, 4.1N, and 4.1B, which undergo complex alternative splicing. Here we performed a detailed characterization of the expression of specific 4.1 proteins in the mouse nephron.Methods. Distribution of renal 4.1 proteins was investigated by staining of paraformaldehyde-fixed mouse kidney sections with antibodies highly specific for each 4.1 protein. Major 4.1 splice forms, amplified from mouse kidney marathon cDNA, were expressed in transfected COS-7 cells in order to assign species of known exon composition to proteins detected in kidney.Results. A 105 kD 4.1R splice form, initiating at ATG-2 translation initiation site and lacking exon 16, but including exon 17B, was restricted to thick ascending limb of Henle's loop. A 95 kD 4.1N splice form, lacking exons 15 and 17D, was expressed in either descending or ascending thin limb of Henle's loop, distal convoluted tubule, and all regions of the collecting duct system. A major 108 kD 4.1B splice form, initiating at a newly characterized ATG translation initiation site, and lacking exons 15, 17B, and 21, was present only in Bowman's capsule and proximal convoluted tubule (PCT). There was no expression of 4.1G in kidney.Conclusion. Distinct distribution of 4.1 proteins along the nephron suggests their involvement in targeting of selected transmembrane proteins in kidney epithelium and, therefore, in regulation of specific kidney functions.