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Ubiquitin‐proteasome system is involved in induction of LFA‐1/ICAM‐1‐dependent adhesion of HL‐60 cells
Author(s) -
Katagiri Koko,
Yokosawa Hideyoshi,
Kinashi Tatsuo,
Kawashima Seiichi,
Irie Shinkichi,
Tanaka Keiji,
Katagiri Takuya
Publication year - 1999
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.65.6.778
Subject(s) - lactacystin , proteasome , biology , ubiquitin , calpain , proteolysis , microbiology and biotechnology , icam 1 , cell adhesion molecule , proteasome inhibitor , biochemistry , enzyme , gene
Membrane‐permeable proteasome inhibitors, lactacystin (LC) and N ‐acetyl‐Leu‐Leu‐norleucinal (ALLN), but not calpain inhibitor Z‐Leuleucinal (ZLL), prevented LFA‐1/ICAM‐1‐dependent cellular adhesion of TPA‐stimulated HL‐60 cells. These proteasome inhibitors affected neither the induction of monocytic differentiation nor the accompanying protein‐tyrosine phosphorylation. They suppressed the increase in the avidity of LFA‐1 to ICAM‐1 without changing the expression of these molecules. Immunoblotting using monoclonal antibody FK‐1, which reacts specifically with polyubiquitinated proteins, demonstrated that the proteasome inhibitors caused the drastic accumulation of the polyubiquitinated proteins in the membrane fraction of TPA‐treated HL‐60 cells. This indicates that accompanying activation of LFA‐1, TPA induces the polyubiquitination of the membrane proteins, which are rapidly degraded by proteasomes. These data taken together show that proteolysis mediated by the ubiquitin‐proteasome system is a prerequisite for the induction of LFA‐1‐dependent adhesion of HL‐60 cells. J. Leukoc. Biol. 65: 778–785; 1999.