title: Human T-cell mitogen-activated protein kinase kinases are related to yeast signal transduction kinases.
abstract: Mitogen-activated protein (MAP) kinase kinases, intermediates in a growth factor-stimulated protein kinase cascade, are dual specificity protein kinases that specifically phosphorylate and activate MAP kinases in response to extracellular signals. Here, we report the cloning of two forms of cDNA that encode this protein from human T-cells. MKK1a encodes a protein with predicted molecular size of 43,439 Da. Overexpression of this clone in COS cells led to elevated levels of protein and phorbol ester-stimulated MAP kinase kinase activity, confirming that MKK1a encodes the predicted protein. MKK1b, which appears to be an alternatively spliced form of the MKK1a gene, encodes a protein with predicted molecular size of 40,745 Da. Northern analysis revealed that the MKK1 cDNA hybridizes with a single 2.6-kilobase mRNA species in all human tissues examined. Sequence comparison shows homology to a group of yeast kinases that participate in signal transduction and to subdomain XI of other dual specificity kinase.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004815:Epidermal Growth Factor / Q000494:pharmacology; D015723:Gene Library; D006801:Humans; D020929:Mitogen-Activated Protein Kinase Kinases; D008969:Molecular Sequence Data; D009132:Muscles / Q000201:enzymology; D009928:Organ Specificity; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D011494:Protein Kinases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger; D011817:Rabbits; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013154:Spleen / Q000201:enzymology; D013601:T-Lymphocytes / Q000201:enzymology*; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; D011994:Recombinant Proteins; D011061:Poly A; D004815:Epidermal Growth Factor; D012313:RNA; D004247:DNA; D011494:Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases