A conserved WXXE motif is an apical delivery determinant of ABC transporter C subfamily isoforms.
A conserved WXXE motif is an apical delivery determinant of ABC transporter C subfamily isoforms.
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DOI：
10.1247/csf.22049
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发表时间：
2023-03-09
影响因子：
1.5
通讯作者：
中科院分区：
文献类型：
--
作者：
ATP 结合盒转运蛋白亚型 C7 (ABCC7)，也称为囊性纤维化跨膜电导调节剂 (CFTR)，专门针对极化上皮细胞的顶端质膜。尽管 ABCC7 在上皮细胞中的顶端定位对于 Cl- 排泄到管腔中至关重要，但调节其顶端定位的机制却知之甚少。在本研究中，在 ABCC7 (NT80) 的 N 端 80 个氨基酸长胞质区域中鉴定出顶端定位决定簇。在 HepG2 细胞中，NT80 的过表达以竞争性方式显着扰乱了 ABCC7 的顶端表达，表明该区域存在分选决定簇。删除分析确定了 NT80 的 20 个氨基酸长肽（aa 41-60）内的潜在排序信息。全长 ABCC7 中该区域的丙氨酸扫描诱变进一步将顶端定位决定簇缩小到四个氨基酸，W57DRE60。该 WDRE 序列在脊椎动物 ABCC7 直向同源物中是保守的。定点诱变表明 W57 和 E60 对于 ABCC7 的顶端表达至关重要，证实了 ABCC7 的新顶端分选决定因素。此外，发现 WXXE 基序（具有两个氨基酸间隔的色氨酸和谷氨酸残基）在具有 12-TM 构型的顶端定位 ABCC 成员的 N 端区域中是保守的。 WXXE 基序对于将 ABCC4 正确运输到顶端质膜具有重要意义。
ATP-binding cassette transporter isoform C7 (ABCC7), also designated as cystic fibrosis transmembrane conductance regulator (CFTR), is exclusively targeted to the apical plasma membrane of polarized epithelial cells. Although the apical localization of ABCC7 in epithelia is crucial for the Cl– excretion into lumens, the mechanism regulating its apical localization is poorly understood. In the present study, an apical localization determinant was identified in the N-terminal 80-amino acid long cytoplasmic region of ABCC7 (NT80). In HepG2 cells, overexpression of NT80 significantly disturbed the apical expression of ABCC7 in a competitive manner, suggesting the presence of a sorting determinant in this region. Deletion analysis identified a potential sorting information within a 20-amino acid long peptide (aa 41–60) of NT80. Alanine scanning mutagenesis of this region in full-length ABCC7 further narrowed down the apical localization determinant to four amino acids, W57DRE60. This WDRE sequence was conserved among vertebrate ABCC7 orthologs. Site-directed mutagenesis showed that W57 and E60 were critical for the apical expression of ABCC7, confirming a novel apical sorting determinant of ABCC7. Furthermore, a WXXE motif (tryptophan and glutamic acid residues with two-amino acid spacing) was found to be conserved among the N-terminal regions of apically localized ABCC members with 12-TM configuration. The significance of the WXXE motif was demonstrated for proper trafficking of ABCC4 to the apical plasma membrane.
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影响因子：
4.8
作者：
Short, DB;Trotter, KW;Milgram, SL
通讯作者：
Milgram, SL
影响因子：
5.5
作者：
Collaco, Anne;Marathe, Jai;Ameen, Nadia
通讯作者：
Ameen, Nadia
影响因子：
15.9
作者：
Choudhury, A;Dominguez, M;Pagano, RE
通讯作者：
Pagano, RE
DOI：
10.1038/nrm2525
发表时间：
2008-11
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
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影响因子：
8
作者：
Saint-Criq, Vinciane;Gray, Michael A.
通讯作者：
Gray, Michael A.