Molecular cloning and nucleic acid binding properties of the GAP-associated tyrosine phosphoprotein p62.
p62 is a tyrosine phosphoprotein that associates with p21ras GTPase-activating protein (GAP). Purification and cDNA cloning of p62 reveal extensive sequence similarity to a putative hnRNP protein, GRP33. Recombinant human p62 purified from insect Sf9 cells binds to DNA and to mRNA and, like many proteins involved in mRNA processing, recombinant p62 is modified by dimethylation on multiple arginine residues. p62 also binds tightly to p21ras GAP in vitro: this binding depends on phosphorylation of p62 on tyrosine residues and occurs through SH2 regions of GAP. These data suggest that p120-GAP and p62 play a role in some aspect of mRNA processing or utilization and that this role may be regulated by tyrosine phosphorylation, and indirectly, by p21ras.
Wong
G
G
Department of Molecular Biology, Chiron Corporation, Emeryville, California 94608.
Müller
O
O
Clark
R
R
Conroy
L
L
Moran
M F
MF
Polakis
P
P
McCormick
F
F
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000502:physiology*; D020690:GTPase-Activating Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D007301:Insect Hormones / Q000737:chemistry; D019476:Insect Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D010750:Phosphoproteins / Q000502:physiology*; D019000:Phosphotyrosine; D011506:Proteins / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D011994:Recombinant Proteins; D012261:Ribonucleoproteins / Q000737:chemistry; D016415:Sequence Alignment; D014443:Tyrosine / Q000031:analogs & derivatives
D004268:DNA-Binding Proteins; C489560:DOK1 protein, human; C489561:Dok1 protein, mouse; C074561:GAP-associated protein p62; C053819:GRP33 protein, Artemia salina; D020690:GTPase-Activating Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D007301:Insect Hormones; D019476:Insect Proteins; D009838:Oligodeoxyribonucleotides; D010750:Phosphoproteins; D011506:Proteins; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D012261:Ribonucleoproteins; D019000:Phosphotyrosine; D014443:Tyrosine