Premium
Signal peptidase can cleave inside a polytopic membrane protein
Author(s) -
Beltzer James P.,
Wessels Hans Peter,
Spiess Martin
Publication year - 1989
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(89)80937-8
Subject(s) - signal peptidase , signal peptide , endoplasmic reticulum , cleavage (geology) , membrane protein , transmembrane protein , signal recognition particle , cleave , biochemistry , biology , microbiology and biotechnology , protein sorting signals , biophysics , membrane , peptide sequence , enzyme , receptor , paleontology , fracture (geology) , gene
The signal peptides of most proteins targeted to the endoplasmic reticulum are specifically cleaved by signal peptidase. Although potential cleavage sites occur frequently in polytopic proteins after membrane‐spanning segments, processing is restricted to the first hydrophobic domain, suggesting that signal peptidase might not have access to subsequently translocated, internal domains. To test this hypothesis, we replaced the third transmembrane segment of an artificial threefold membrane‐spanning protein by a sequence which is normally an amino‐terminal signal. Upon in vitro translation and insertion into microsomes, efficient cleavage at this sequence was observed, thus demonstrating the ability of signal peptidase to cleave within polytopic membrane proteins.