NCU-G1 is a highly glycosylated integral membrane protein of the lysosome.
NCU-G1 is a highly glycosylated integral membrane protein of the lysosome.
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NCU-G1 是溶酶体的高度糖基化的整合膜蛋白。
作者：
O. Schieweck;M. Damme;B. Schröder;A. Hasilik;B. Schmidt;T. Lübke
直到最近，只有少量的大约。目前已鉴定出40种溶酶体膜蛋白，功能鉴定的更少。在蛋白质组学研究中，利用人胎盘的溶酶体膜，我们鉴定了几种候选的溶酶体膜蛋白，并证明了其中两种溶酶体膜蛋白的定位。在本研究中，我们证明了人类C1orf85蛋白的小鼠同源蛋白的溶酶体定位，该蛋白被命名为肾脏优势蛋白NCU-G1(GenBank登录号：AB027141)。NCU-G1编码一个404个氨基酸的蛋白质，计算出其分子质量为39 kDa。其氨基酸序列的生物信息学分析表明，它是一种I型跨膜蛋白，在C末端的12个残基的第400位含有一个基于酪氨酸的共性溶酶体分选基序。以C端标记的NCU-G1和溶酶体标记物LAMP-1(溶酶体相关膜蛋白-1)为参照，通过免疫荧光和用抗NCU-G1抗血清对小鼠肝脏进行亚细胞分级，证实了其溶酶体的定位。在瞬时转染的HT1080和HeLa细胞中，His标记的NCU-G1以两种分子形式存在，表观蛋白质大小分别为70和80 kDa，而在小鼠肝脏中检测到内源性野生型NCU-G1为75 kDa的蛋白质。用N-糖苷酶F消化NCU-G1蛋白，其表观分子质量与计算的分子质量之间的显著差异是由于广泛的糖基化作用。溶酶体的定位被假定的分选基序中的丙氨酸残基突变为酪氨酸残基所损害。
Until recently, a modest number of approx. 40 lysosomal membrane proteins had been identified and even fewer were characterized in their function. In a proteomic study, using lysosomal membranes from human placenta we identified several candidate lysosomal membrane proteins and proved the lysosomal localization of two of them. In the present study, we demonstrate the lysosomal localization of the mouse orthologue of the human C1orf85 protein, which has been termed kidney-predominant protein NCU-G1 (GenBank accession number: AB027141). NCU-G1 encodes a 404 amino acid protein with a calculated molecular mass of 39 kDa. The bioinformatics analysis of its amino acid sequence suggests it is a type I transmembrane protein containing a single tyrosine-based consensus lysosomal sorting motif at position 400 within the 12-residue C-terminal tail. Its lysosomal localization was confirmed using immunofluorescence with a C-terminally His-tagged NCU-G1 and the lysosomal marker LAMP-1 (lysosome-associated membrane protein-1) as a reference, and by subcellular fractionation of mouse liver after a tyloxapol-induced density shift of the lysosomal fraction using an anti-NCU-G1 antiserum. In transiently transfected HT1080 and HeLa cells, the His-tagged NCU-G1 was detected in two molecular forms with apparent protein sizes of 70 and 80 kDa, and in mouse liver the endogenous wild-type NCU-G1 was detected as a 75 kDa protein. The remarkable difference between the apparent and the calculated molecular masses of NCU-G1 was shown, by digesting the protein with N-glycosidase F, to be due to an extensive glycosylation. The lysosomal localization was impaired by mutational replacement of an alanine residue for the tyrosine residue within the putative sorting motif.
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影响因子：
3.5
作者：
Sun, M;Goldin, E;Slaugenhaupt, SA
通讯作者：
Slaugenhaupt, SA
溶酶体的蛋白质组学。
DOI：
10.1016/j.bbamcr.2008.09.018
发表时间：
2009-04
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Lübke T;Lobel P;Sleat DE
通讯作者：
Sleat DE
影响因子：
64.5
作者：
Reczek, David;Schwake, Michael;Saftig, Paul
通讯作者：
Saftig, Paul
影响因子：
30.8
作者：
Rutsch, Frank;Gailus, Susann;Nuernberg, Peter
通讯作者：
Nuernberg, Peter