A protein tyrosine phosphatase expressed within dopaminoceptive neurons of the basal ganglia and related structures.
Immunocytochemical and biochemical studies were conducted to characterize a brain-specific protein tyrosine phosphatase, designated STEP for striatal enriched phosphatase. STEP immunoreactivity was most intense in select regions of the CNS receiving a dopaminergic input, and was localized to cell bodies, dendrites, and axonal processes. Western blot analyses of rat brain homogenates revealed a triplet of polypeptides with relative mobilities (M(r)) of 46 kDa, 37 kDa, and 33 kDa enriched within the striatum. Phase separation of protein homogenates by Triton X-114 extraction indicated that this triplet was enriched in soluble but not membrane fractions. Affinity-purified STEP fusion protein exhibited phosphatase activity while a mutated form of the STEP fusion protein (Cys300Ser) showed no demonstrable phosphatase activity.
Lombroso
P J
PJ
Child Study Center, Yale University School of Medicine, New Haven, Connecticut 06536.
Naegele
J R
JR
Sharma
E
E
Lerner
M
M
D000818:Animals; D001479:Basal Ganglia / Q000201:enzymology*; D001483:Base Sequence; D015153:Blotting, Western; D001921:Brain / Q000201:enzymology*; D002846:Chromatography, Affinity; D003342:Corpus Striatum / Q000201:enzymology*; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D005260:Female; D015870:Gene Expression; D007106:Immune Sera / Q000302:isolation & purification; D007150:Immunohistochemistry; D007700:Kinetics; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000032:analysis; D009474:Neurons / Q000201:enzymology*; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D009928:Organ Specificity; D010750:Phosphoproteins; D016133:Polymerase Chain Reaction; D017027:Protein Tyrosine Phosphatases / Q000032:analysis / Q000096:biosynthesis* / Q000378:metabolism; D054558:Protein Tyrosine Phosphatases, Non-Receptor; D051381:Rats; D011954:Receptors, Dopamine / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism
D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D007106:Immune Sera; D009419:Nerve Tissue Proteins; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D010750:Phosphoproteins; D011954:Receptors, Dopamine; D011993:Recombinant Fusion Proteins; D017027:Protein Tyrosine Phosphatases; D054558:Protein Tyrosine Phosphatases, Non-Receptor; C489931:Ptpn5 protein, rat