RT Journal Article SR Electronic T1 Interplay between MPIase, YidC, and PMF during Sec-independent insertion of membrane proteins JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202101162 DO 10.26508/lsa.202101162 VO 5 IS 1 A1 Yuta Endo A1 Yuko Shimizu A1 Hanako Nishikawa A1 Katsuhiro Sawasato A1 Ken-ichi Nishiyama YR 2022 UL https://www.life-science-alliance.org/content/5/1/e202101162.abstract AB Integral membrane proteins with the N-out topology are inserted into membranes usually in YidC- and PMF-dependent manners. The molecular basis of the various dependencies on insertion factors is not fully understood. A model protein, Pf3-Lep, is inserted independently of both YidC and PMF, whereas the V15D mutant requires both YidC and PMF in vivo. We analyzed the mechanisms that determine the insertion factor dependency in vitro. Glycolipid MPIase was required for insertion of both proteins because MPIase depletion caused a significant defect in insertion. On the other hand, YidC depletion and PMF dissipation had no effects on Pf3-Lep insertion, whereas V15D insertion was reduced. We reconstituted (proteo)liposomes containing MPIase, YidC, and/or F0F1-ATPase. MPIase was essential for insertion of both proteins. YidC and PMF stimulated Pf3-Lep insertion as the synthesis level increased. V15D insertion was stimulated by both YidC and PMF irrespective of the synthesis level. These results indicate that charges in the N-terminal region and the synthesis level are the determinants of YidC and PMF dependencies with the interplay between MPIase, YidC, and PMF.