Emerging View on the Molecular Functions of Sec62 and Sec63 in Protein Translocation

• Published in: International journal of molecular sciences Vol. 22; no. 23; p. 12757
• Main Authors: Jung, Sung-Jun, Kim, Hyun
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25.11.2021; MDPI
• Subjects: Binding sites; Endoplasmic reticulum; Endoplasmic Reticulum - genetics; Endoplasmic Reticulum - metabolism; Heat-Shock Proteins - genetics; Heat-Shock Proteins - metabolism; Membrane proteins; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; Membranes; Post-translation; Protein Processing, Post-Translational; protein translocation; Protein Transport; Proteins; Review; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; SEC Translocation Channels - genetics; SEC Translocation Channels - metabolism; Sec61; Sec62; Sec63; Signal recognition particle; Translation; Yeast; Sec62; Sec61; endoplasmic reticulum; Sec63; protein translocation
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms222312757

Most secreted and membrane proteins are targeted to and translocated across the endoplasmic reticulum (ER) membrane through the Sec61 protein-conducting channel. Evolutionarily conserved Sec62 and Sec63 associate with the Sec61 channel, forming the Sec complex and mediating translocation of a subset of proteins. For the last three decades, it has been thought that ER protein targeting and translocation occur via two distinct pathways: signal recognition particle (SRP)-dependent co-translational or SRP-independent, Sec62/Sec63 dependent post-translational translocation pathway. However, recent studies have suggested that ER protein targeting and translocation through the Sec translocon are more intricate than previously thought. This review summarizes the current understanding of the molecular functions of Sec62/Sec63 in ER protein translocation.