Identification and characterization of a substrate specific for the T cell protein tyrosine kinase ZAP-70.
ZAP-70 is a protein tyrosine kinase (PTK) that plays a critical role in T cell activation. To study the role of ZAP-70 catalytic activity in this process, a substrate capable of distinguishing between the activities of ZAP-70 and other PTKs would be useful, especially since it has recently been shown that ZAP-70 interacts with another T cell PTK, Lck. We have thus identified a site of phosphorylation on the cytoplasmic fragment of the erythrocyte band 3 protein that is recognized by ZAP-70, but not Lck. A synthetic peptide based on this site has been demonstrated to be a good in vitro substrate for ZAP-70 and a poor substrate for the T cell PTKs Lck and Itk. This peptide molecule should thus prove useful to many investigators working in the field of T cell activation.
Watts
J D
JD
Department of Molecular Biotechnology, University of Washington, Seattle 98195-7730, USA. julian@u.washington.edu
Brabb
T
T
Bures
E J
EJ
Wange
R L
RL
Samelson
L E
LE
Aebersold
R
R
D000595:Amino Acid Sequence; D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D004676:Myelin Basic Protein / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013379:Substrate Specificity; D013601:T-Lymphocytes / Q000201:enzymology*; D051746:ZAP-70 Protein-Tyrosine Kinase; D019061:src-Family Kinases / Q000378:metabolism
D001457:Anion Exchange Protein 1, Erythrocyte; D008565:Membrane Proteins; D004676:Myelin Basic Protein; D010446:Peptide Fragments; D011948:Receptors, Antigen, T-Cell; D011994:Recombinant Proteins; C054979:antigen T cell receptor, zeta chain; D011505:Protein-Tyrosine Kinases; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human; D019061:src-Family Kinases