Expression level of Sec62 modulates membrane insertion of marginally hydrophobic segments

• Published in: Biochimica et biophysica acta. Biomembranes Vol. 1864; no. 12; p. 184051
• Main Authors: Jung, Sung-jun, Yun, Mekang, Yim, Chewon, Hong, Sujin, Huh, Won-Ki, Kim, Hyun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2022
• Subjects: Biochemistry & Molecular Biology; Biological Sciences; Biologiska vetenskaper; Biophysics; Biosynthesis; complex; endoplasmic-reticulum; integration; Marginally hydrophobic; Membrane insertion; Overexpression; protein; Sec62; translocation; Transmembrane; yeast; Marginally hydrophobic; Biosynthesis; Overexpression; Sec62; Transmembrane; Membrane insertion
• ISSN: 0005-2736; 1879-2642
• DOI: 10.1016/j.bbamem.2022.184051

In the endoplasmic reticulum (ER) membrane, transmembrane (TM) domain insertion occurs through the Sec61 channel with its auxiliary components, including Sec62. Sec62 interacts with the Sec61 channel and is located on the front side of the Sec61 lateral gate, an entry site for TM domains to the lipid bilayer. Overexpression of Sec62 led to a growth defect in yeast, and we investigated its effects on protein translocation and membrane insertion by pulse labeling of Sec62 client proteins. Our data show that the insertion efficiency of marginally hydrophobic TM segments is reduced upon Sec62 overexpression. This result suggests a potential regulatory role of Sec62 as a gatekeeper of the lateral gate, thereby modulating the insertion threshold of TM segments. [Display omitted] •Overexpression of Sec62 causes a growth defect in yeast.•Overexpressed Sec62 is properly localized in the ER membrane.•Membrane insertion threshold is changed in Sec62-overexpressing cells.