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

PLoS One. 2014 Jan 14;9(1):e85206. doi: 10.1371/journal.pone.0085206. eCollection 2014.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Calcium Channels
  • Cell Line
  • Cytosol / metabolism
  • Endoplasmic Reticulum / metabolism*
  • Gene Expression Regulation
  • Humans
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Molecular Sequence Data
  • Protein Structure, Tertiary
  • Protein Transport
  • Ribosomal Proteins / metabolism

Substances

  • Calcium Channels
  • Membrane Proteins
  • Ribosomal Proteins
  • TMCO1 protein, human

Grant support

This work was supported by grants from the Research Grants Council (General Research Fund and Theme-based Research Scheme) of Hong Kong, the National Key Basic Research Program (2013CB530900) of China, the University Grants Committee (Area of Excellence Scheme and Special Equipment Grant SEG_HKUST05) of Hong Kong, the TUYF Charitable Trust, and by funds from the Hong Kong University of Science and Technology. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.