The EphA8 receptor phosphorylates and activates low molecular weight phosphotyrosine protein phosphatase in vitro.
Low molecular weight phosphotyrosine protein phosphatase (LMW-PTP) has been implicated in modulating the EphB1-mediated signaling pathway. In this study, we demonstrated that the EphA8 receptor phosphorylates LMW-PTP in vitro. In addition, we discovered that mixing these two proteins leads to EphA8 dephosphorylation in the absence of phosphatase inhibitors. Finally, we demonstrated that LMW-PTP, modified by the EphA8 autokinase activity, possesses enhanced catalytic activity in vitro. These results suggest that LMW-PTP may also participate in a feedback-control mechanism of the EphA8 receptor autokinase activity in vivo.
Park
Soochul
S
Department of Life Science, Sookmyung Women  s University, 53-12 Chungpa-Dong 2-Ka, Yongsan-Ku, Seoul 140-742, Korea. scpark@sookmyung.ac.kr
D000818:Animals; D002460:Cell Line; D004789:Enzyme Activation; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008970:Molecular Weight; D010766:Phosphorylation; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D036143:Receptor, EphA8 / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014443:Tyrosine / Q000378:metabolism
D011993:Recombinant Fusion Proteins; D014443:Tyrosine; D005982:Glutathione Transferase; D036143:Receptor, EphA8; D017027:Protein Tyrosine Phosphatases