Serine phosphorylation-dependent association of the band 4.1-related protein-tyrosine phosphatase PTPH1 with 14-3-3beta protein.
PTPH1 is a human protein-tyrosine phosphatase with homology to the band 4.1 superfamily of cytoskeletal-associated proteins. PTPH1 was found to associate with 14-3-3beta using a yeast two-hybrid screen, and its interaction could be reconstituted in vitro using recombinant proteins. Examination of the interaction between 14-3-3beta and various deletion mutants of PTPH1 by two-hybrid tests suggested that the integrity of the PTP is important for this binding. Although both PTPH1 and Raf-1 form complexes with 14-3-3beta, they appear to do so independently. Binding of 14-3-3beta to PTPH1 in vitro was abolished by pretreating PTPH1 with potato acid phosphatase and was greatly enhanced by pretreating with Cdc25C-associated protein kinase. Thus the association between PTPH1 and 14-3-3beta is phosphorylation-dependent. Two novel motifs RSLS359VE and RVDS853EP in PTPH1 were identified as major 14-3-3beta-binding sites, both of which are distinct from the consensus binding motif RSXSXP recently found in Raf-1. Mutation of Ser359 and Ser853 to alanine significantly reduced the association between 14-3-3beta and PTPH1. Furthermore, association of PTPH1 and 14-3-3beta was detected in several cell lines and was regulated in response to extracellular signals. These results raise the possibility that 14-3-3beta may function as an adaptor molecule in the regulation of PTPH1 and may provide a link between serine/threonine and tyrosine phosphorylation-dependent signaling pathways.
Zhang
S H
SH
Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.
Kobayashi
R
R
Graves
P R
PR
Piwnica-Worms
H
H
Tonks
N K
NK
D048948:14-3-3 Proteins; D000595:Amino Acid Sequence; D001665:Binding Sites; D002460:Cell Line; D019976:Cloning, Organism; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry; D009479:Neuropeptides; D010446:Peptide Fragments / Q000737:chemistry; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism*; D054589:Protein Tyrosine Phosphatase, Non-Receptor Type 3; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D016415:Sequence Alignment; D014162:Transfection; D014407:Tumor Cells, Cultured; D014446:Tyrosine 3-Monooxygenase
D048948:14-3-3 Proteins; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D009479:Neuropeptides; D010446:Peptide Fragments; D011506:Proteins; D011993:Recombinant Fusion Proteins; C482982:YWHAB protein, human; C028841:erythrocyte membrane band 4.1 protein; C120557:erythrocyte membrane protein band 4.1-like 1; D010768:Phosphoserine; D014446:Tyrosine 3-Monooxygenase; C516656:PTPN3 protein, human; D054589:Protein Tyrosine Phosphatase, Non-Receptor Type 3; D017027:Protein Tyrosine Phosphatases