Functional Characterization of Bacterial Signal Peptide OmpA in a Baculovirus-Mediated Expression System

Cell Structure and Function

Yu Kawasaki³  Tetsutaro Iizuka³  Keiju Okano¹  Shogo Matsumoto¹  Toshihiro Nagamine¹  Prabhakara V. Choudary² 

[1] RIKEN (The Institute of Physical and Chemical Research);the Section of Neurobiology, Physiology and Behavior, and the Center for Neuroscience, Division of Biological Sciences, University of California;Department of Materials Chemistry, College of Engineering, Hosei University

关键词: aggresome;    baculovirus;    ER dislocation;    post-translational transport;    signal peptide;   

DOI  :  10.1247/csf.28.131

学科分类：分子生物学，细胞生物学和基因

来源: Japan Society for Cell Biology

【 摘 要 】

References(33)Cited-By(3)Signal sequences are evolutionarily conserved and are often functionally interchangeable between prokaryotes and eukaryotes. However, we have found that the bacterial signal peptide, OmpA, functions incompletely in insect cells. Upon baculovirus-mediated expression of chloramphenicol acetyltransferase (CAT) in insect cells, OmpA signal peptide led to the cytosolic accumulation of the CAT molecules in an aglycosylated, signal-peptide cleaved form, in addition to the secretion of the glycosylated CAT. When green fluorescent protein (GFP) was used as another reporter, the GFP molecules expressed from the OmpA-GFP construct was distributed primarily in the cytosol as aggresome-like structures. These results together suggest that, subsequent to the cleavage of OmpA signal peptide in the ER, some of the processed proteins are returned to the cytoplasm. Since the prototypical insect signal peptide, melittin, did not result in this ER-to-cytosol dislocation of the reporter proteins, we proposed a model explaining the dislocation process in insect cells, apparently selective to the OmpA-directed secretory pathway bypassing the co-translational transport.

【 授权许可】

Unknown