The melanoma growth stimulatory activity receptor consists of two proteins. Ligand binding results in enhanced tyrosine phosphorylation.
The human melanoma growth-stimulatory activities (MGSA alpha, beta, gamma/GRO) are products of immediate early genes coding for cytokines that exhibit sequence similarity to platelet factor-4 and beta-thromboglobulin. MGSA/GRO alpha has been demonstrated to partially complete for binding to the approximately 58-kDa neutrophil receptor for another beta-thromboglobulin-related chemotactic protein, IL-8. We demonstrate that when [125I]MGSA/GRO alpha was cross-linked to receptors/binding proteins from human placenta, there were two major [125I]MGSA cross-linked bands of approximately 64,000 and approximately 84,000 Mr. Because [125I]MGSA exists primarily in monomer and dimer forms at the concentrations used here, it is not clear whether the receptor/binding proteins represented by the cross-linked bands are approximately 50,000 and approximately 70,000 or approximately 58,000 and approximately 78,000 Mr. Ligand binding to the receptor proteins is associated with enhanced tyrosine phosphorylation of a number of substrates, including proteins in the same Mr range as the MGSA/GRO receptor/binding proteins.
Cheng
Q C
QC
Department of Cell Biology and Medicine, Vanderbilt University, Nashville, TN 37232.
Han
J H
JH
Thomas
H G
HG
Balentien
E
E
Richmond
A
A
D001667:Binding, Competitive; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000032:analysis*; D054360:Chemokine CXCL1; D019743:Chemokines, CXC; D066246:ErbB Receptors / Q000276:immunology; D006133:Growth Substances / Q000032:analysis / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8 / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism*; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000032:analysis / Q000378:metabolism* / Q000494:pharmacology; D010766:Phosphorylation; D010920:Placenta / Q000378:metabolism; D011971:Receptors, Immunologic / Q000032:analysis; D023062:Receptors, Interleukin-8A; D015398:Signal Transduction; D014443:Tyrosine / Q000378:metabolism*
C475829:CXCL1 protein, human; D002352:Carrier Proteins; D054360:Chemokine CXCL1; D019743:Chemokines, CXC; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D011971:Receptors, Immunologic; D023062:Receptors, Interleukin-8A; D014443:Tyrosine; D066246:ErbB Receptors; D002118:Calcium