TY - JOUR
T1 - p62, a phosphotyrosine-independent ligand of the SH2 domain of p56(lck), belongs to a new class of ubiquitin-binding proteins
AU - Vadlamudi, Ratna K.
AU - Joung, Insil
AU - Strominger, Jack L.
AU - Shin, Jaekyoon
PY - 1996
Y1 - 1996
N2 - p62 is a novel cellular protein which was initially identified as a phosphotyrosine-independent ligand of the SH2 domain of p56(lck). In the yeast two-hybrid system, p62 specifically interacted with ubiquitin in vivo. Furthermore, p62 bound to ubiquitin-conjugated Sepharose beads in vitro and was efficiently competed by soluble ubiquitin. The interaction was independent of ATP hydrolysis, and its dissociation did not require a reducing agent. Thus, p62 binds to ubiquitin noncovalently. Further analysis showed that the C-terminal 80 amino acids of p62 were indispensable for its interaction with ubiquitin. However, p62 has homology neither with ubiquitin C-terminal hydrolases nor with the S5a subunit of the 26 S proteasome complex, the only proteins known to bind to ubiquitin noncovalently. These results suggest that p62 belongs to a new class of ubiquitin-binding proteins and that p62 affects signal transduction at least partly through ubiquitination-mediated protein degradation.
AB - p62 is a novel cellular protein which was initially identified as a phosphotyrosine-independent ligand of the SH2 domain of p56(lck). In the yeast two-hybrid system, p62 specifically interacted with ubiquitin in vivo. Furthermore, p62 bound to ubiquitin-conjugated Sepharose beads in vitro and was efficiently competed by soluble ubiquitin. The interaction was independent of ATP hydrolysis, and its dissociation did not require a reducing agent. Thus, p62 binds to ubiquitin noncovalently. Further analysis showed that the C-terminal 80 amino acids of p62 were indispensable for its interaction with ubiquitin. However, p62 has homology neither with ubiquitin C-terminal hydrolases nor with the S5a subunit of the 26 S proteasome complex, the only proteins known to bind to ubiquitin noncovalently. These results suggest that p62 belongs to a new class of ubiquitin-binding proteins and that p62 affects signal transduction at least partly through ubiquitination-mediated protein degradation.
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U2 - 10.1074/jbc.271.34.20235
DO - 10.1074/jbc.271.34.20235
M3 - Article
C2 - 8702753
AN - SCOPUS:0029809134
SN - 0021-9258
VL - 271
SP - 20235
EP - 20237
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 34
ER -