3.A.27.1.1
ER membrane protein insertase complex of ten recognized proteins, EMC1 - 10 (Guna et al. 2018).  Inserts C-terminal moderately hydrophobic TMSs of tail anchored (TA) proteins into the endoplasmic reticular membrane (Guna et al. 2018). EMC also inserts the first N-terminal TMS of G-proteins and some receptors co-translationally and cooperates with the Sec61 translocon to ensure accurate topogenesis of many membrane proteins (Chitwood et al. 2018). Disrupted ER membrane protein complex-mediated topogenesis drives congenital neural crest defects (Marquez et al. 2020). The high resolution 3-d structure of this EMC complex has been determined (O'Donnell et al. 2020). EMC10 plays a regulatory role in the ER membrane complex, opposing the transmembrane-domain insertion activity of the complex (Coukos et al. 2021). Inherited retinal dystrophies (IRDs) are a heterogeneous group of visual disorders caused by different pathogenic mutations in genes and regulatory sequences. The endoplasmic reticulum (ER) membrane protein complex (EMC) subunit 3 (EMC3) is the core unit of the EMC insertase that integrates transmembrane peptides into lipid bilayers (Li et al. 2023).  The C-terminus of EMC3 is essential for EMC functions, and EMC3 may be the gene for retinal degenerative diseases (Li et al. 2023).