Transmembrane and coiled-coil domain family 1 is a novel protein of the endoplasmic reticulum

• Published in: PloS one Vol. 9; no. 1; p. e85206
• Main Authors: Zhang, Chao, Kho, Yik-Shing, Wang, Zhe, Chiang, Yan Ting, Ng, Gary K H, Shaw, Pang-Chui, Wang, Yuzhuo, Qi, Robert Z
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 14-01-2014; Public Library of Science (PLoS)
• Subjects: Amino Acid Sequence; Animals; Biology; C-Terminus; Cell growth; Cell Line; Cell lines; Cells (Biology); Cytoplasm; Cytosol - metabolism; Defects; Dimers; Endoplasmic reticulum; Endoplasmic Reticulum - metabolism; Gene Expression Regulation; Humans; Laboratories; Life sciences; Localization; Membrane Proteins - chemistry; Membrane Proteins - genetics; Membrane Proteins - metabolism; Membranes; Molecular Sequence Data; Morphology; Neurosciences; Oligomers; Phosphorylation; Protein Structure, Tertiary; Protein Transport; Proteins; Ribosomal proteins; Ribosomal Proteins - metabolism; Transmembrane domains; Canada; Hong Kong; Vancouver British Columbia Canada; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0085206

The endoplasmic reticulum (ER) is a continuous membrane network in eukaryotic cells comprising the nuclear envelope, the rough ER, and the smooth ER. The ER has multiple critical functions and a characteristic structure. In this study, we identified a new protein of the ER, TMCC1 (transmembrane and coiled-coil domain family 1). The TMCC family consists of at least 3 putative proteins (TMCC1-3) that are conserved from nematode to human. We show that TMCC1 is an ER protein that is expressed in diverse human cell lines. TMCC1 contains 2 adjacent transmembrane domains near the C-terminus, in addition to coiled-coil domains. TMCC1 was targeted to the rough ER through the transmembrane domains, whereas the N-terminal region and C-terminal tail of TMCC1 were found to reside in the cytoplasm. Moreover, the cytosolic region of TMCC1 formed homo- or hetero-dimers or oligomers with other TMCC proteins and interacted with ribosomal proteins. Notably, overexpression of TMCC1 or its transmembrane domains caused defects in ER morphology. Our results suggest roles of TMCC1 in ER organization.