Premium
Mutation of the protein‐ O ‐mannosyltransferase enhances secretion of the human urokinase‐type plasminogen activator in Hansenula polymorpha
Author(s) -
Agaphonov Michael O.,
Sokolov Sviatoslav S.,
Romanova Nina V.,
Sohn JungHoon,
Kim SoYoung,
Kalebina Tatyana S.,
Choi EuiSung,
TerAvanesyan Michael D.
Publication year - 2005
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/yea.1297
Subject(s) - endoplasmic reticulum , biology , secretion , saccharomyces cerevisiae , kdel , mutant , secretory protein , microbiology and biotechnology , secretory pathway , plasminogen activator , biochemistry , gene , golgi apparatus , genetics
Human urokinase‐type plasminogen activator (uPA) is poorly secreted and aggregates in the endoplasmic reticulum of yeast cells due to inefficient folding. A screen for Hansenula polymorpha mutants with improved uPA secretion revealed a gene encoding a homologue of the Saccharomyces cerevisiae protein‐ O ‐mannosyltransferase Pmt1p. Expression of the H. polymorpha PMT1 gene ( HpPMT1 ) abolished temperature sensitivity of the S. cerevisiae pmt1 pmt2 double mutant. As in S. cerevisiae , inactivation of the HpPMT1 gene affected electrophoretic mobility of the O ‐glycosylated protein, extracellular chitinase. In contrast to S. cerevisiae , disruption of HpPMT1 alone caused temperature sensitivity. Inactivation of the HpPMT1 gene decreased intracellular aggregation of uPA, suggesting that enhanced secretion of uPA was due to improvement of its folding in the endoplasmic reticulum. Unlike most of the endoplasmic reticulum membrane proteins, HpPmt1p possesses the C‐terminal KDEL retention signal. The GenBank Accession No. for the H. polymorpha PMT1 sequence is AY701415. Copyright © 2005 John Wiley & Sons, Ltd.