Alternative titles; symbols
HGNC Approved Gene Symbol: CORO1C
Cytogenetic location: 12q24.11 Genomic coordinates (GRCh38) : 12:108,645,109-108,731,518 (from NCBI)
The CORO1C gene encodes a member of the coronin family of actin-binding proteins (Iizaka et al., 2000). For background information on the coronins, see CORO1A (605000).
By RT-PCR and searching an EST database, Iizaka et al. (2000) obtained a cDNA encoding CORO1C. Sequence analysis predicted that the 474-amino acid CORO1C protein is 65% identical to CORO1A, 45% identical to CORO2B (605002), and 97% identical to mouse coronin-3. CORO1C contains 5 N-terminal trp-asp (WD) repeats and a C-terminal coiled-coil motif. Northern blot and RT-PCR analysis detected a major 4.0-kb CORO1C transcript as well as 2 minor transcripts; no splice variants were detected, however, suggesting the presence of some cross-hybridizing gene(s). Immunofluorescence analysis demonstrated that CORO1C is expressed in the cytoplasm in a filamentous pattern and in the peripheral cell cortex, and that CORO1C colocalizes with F-actin.
Hoyer et al. (2018) found that the endoplasmic reticulum (ER) membrane protein TMCC1 (616242) localized to membrane contact sites (MCSs) between dynamic ER tubules and the position of endosome fission in HeLa and COS-7 cells. Expression of fluorescence-tagged TMCC1 in COS-7 cells confirmed that TMCC1 localized to dynamic domains on ER tubules and regulated endosome cargo sorting. Accumulation of TMCC1 dynamic domains at ER MCSs coincided with the position and timing of endosome fission. Knockdown of TMCC1 in COS-7 cells disrupted endosome fission, corroborating that TMCC1 regulates the process of ER-associated endosome fission for retromer-mediated cargo sorting. Analysis in COS-7 cells revealed that coronin-1C localized to discrete patches on endosome buds. Depletion of coronin-1C in COS-7 cells disrupted ER recruitment to the endosome bud and reduced the efficiency of endosome fission, demonstrating that coronin-1C regulates ER recruitment to the bud. Coronin-1C was recruited to endosome buds independently of TMCC1, whereas TMCC1/ER recruitment required coronin-1C. The actions of TMCC1 and coronin-1C were coupled during fission of endosome sorting domains to regulate a precise timing mechanism to ensure successful receptor-mediated cargo sorting before ER recruitment and bud fission.
Iizaka et al. (2000) mapped the CORO1C gene to 12q24.1 by FISH.
Hoyer, M. J., Chitwood, P. J., Ebmeier, C. C., Sriepen, J. F., Qi, R. Z., Old, W. M., Voeltz, G. K. A novel class of ER membrane proteins regulates ER-associated endosome fission. Cell 175: 254-265, 2018. [PubMed: 30220460] [Full Text: https://doi.org/10.1016/j.cell.2018.08.030]
Iizaka, M., Han, H.-J., Akashi, H., Furukawa, Y., Nakajima, Y., Sugano, S., Ogawa, M., Nakamura, Y. Isolation and chromosomal assignment of a novel human gene, CORO1C, homologous to coronin-like actin-binding proteins. Cytogenet. Cell Genet. 88: 221-224, 2000. [PubMed: 10828594] [Full Text: https://doi.org/10.1159/000015555]