Cotranslational integration and initial sorting at the endoplasmic reticulum translocon of proteins destined for the inner nuclear membrane.

ABSTRACT: The current diffusion-retention model for protein trafficking to the inner nuclear membrane (INM) proposes that INM proteins diffuse laterally from the membrane of the endoplasmic reticulum into the INM and are then retained in the INM by binding to nuclear proteins or DNA. Because some data indicate that the sorting of baculovirus envelope proteins to the INM is protein-mediated, we have examined the early stages of INM protein integration and sorting by using photocrosslinking. Both viral and host INM-directed proteins were integrated cotranslationally through the endoplasmic reticulum translocon, and their nonrandom photocrosslinking to two translocon proteins, Sec61alpha and translocating chain-associated membrane protein (TRAM), revealed that the first transmembrane sequence (TMS) of

SUBMITTER: Saksena S 

PROVIDER: S-EPMC515093 | biostudies-literature | 2004 Aug

REPOSITORIES: biostudies-literature