The C terminus of RON tyrosine kinase plays an autoinhibitory role.
RON is a receptor tyrosine kinase in the MET family. We have expressed and purified active RON using the Sf9/baculovirus system. The constructs used in this study comprise the kinase domain alone and the kinase domain plus the C-terminal region. The construct containing the kinase domain alone has a higher specific activity than the construct containing the kinase and C-terminal domains. Purified RON undergoes autophosphorylation, and the exogenous RON C terminus serves as a substrate. Peptides containing a dityrosine motif derived from the C-terminal tail inhibit RON in vitro or when delivered into intact cells, consistent with an autoinhibitory mechanism. Phenylalanine substitutions within these peptides increase the inhibitory potency. Moreover, introduction of these Phe residues into the dityrosine motif of the RON kinase leads to a decrease in kinase activity. Taken together, our data suggest a model in which the C-terminal tail of RON regulates kinase activity via an interaction with the kinase catalytic domain.
Yokoyama
Noriko
N
Department of Physiology and Biophysics, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794, USA.
Ischenko
Irene
I
Hayman
Michael J
MJ
Miller
W Todd
WT
D016475:3T3 Cells; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017124:Conserved Sequence; D017931:DNA Primers; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D020794:Receptor Protein-Tyrosine Kinases / Q000737:chemistry / Q000378:metabolism*; D018411:Spodoptera; D014443:Tyrosine
D017931:DNA Primers; D010446:Peptide Fragments; D014443:Tyrosine; C080835:RON protein; D020794:Receptor Protein-Tyrosine Kinases