Molecular identification of transmembrane protein 68 as an endoplasmic reticulum-anchored and brain-specific protein

被引:17
作者
Chang, Ping'an [1 ]
Heier, Christoph [2 ]
Qin, Wenzhen [1 ]
Han, Liping [1 ]
Huang, Feifei [1 ]
Sun, Quan [1 ]
机构
[1] Chongqing Univ Posts & Telecommun, Sch Bioinformat, Key Lab Mol Biol, Chongqing, Peoples R China
[2] Karl Franzens Univ Graz, Inst Mol Biosci, Heinrichstr 31-11, Graz, Austria
关键词
ACYL-COA; TRIACYLGLYCEROL SYNTHESIS; ACYLTRANSFERASE; DOMAIN; ENZYMES; ACID; LOCALIZATION; DIVERSITY; MUTANT; SIGNAL;
D O I
10.1371/journal.pone.0176980
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Acyltransferases catalyze essential reactions in the buildup and remodeling of glycerophospholipids and contribute to the maintenance and diversity of cellular membranes. Transmembrane protein 68 (TMEM68) is an evolutionarily conserved protein of unknown function, that forms a distinct subgroup within the glycerophospholipid acyltransferase family. In the current study we expressed murine TMEM68 for the first time in mammalian cells to characterize its subcellular localization, topology, and possible biological function(s). We show that TMEM68 is an integral membrane protein and orients both, the N- and C-terminus towards the cytosol. Live cell imaging demonstrated that TMEM68 is localized mainly at the endoplasmic reticulum (ER), but not at cellular lipid droplets (LDs). The positioning of TMEM68 at the ER was dependent on its first transmembrane domain (TMD), which by itself was sufficient to target cytosolic green fluorescence protein (GFP) to the ER. In contrast, a second TMD was dispensable for ER localization of TMEM68. Finally, we found that among multiple murine tissues the expression level of TMEM68 transcripts was highest in brain. We conclude that TMEM68 is an integral ER membrane protein and a putative acyltransferase involved in brain glycerolipid metabolism.
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页数:18
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