A new MAPK gene, ZmSIMK1 (Zea mays L. salt-induced mitogen-activated protein kinase 1), is isolatod from a maize eDNA library. The full-length ZmSIMK1 gene contains 1636 bp and an open reading frame of 1122 nucleoti...A new MAPK gene, ZmSIMK1 (Zea mays L. salt-induced mitogen-activated protein kinase 1), is isolatod from a maize eDNA library. The full-length ZmSIMK1 gene contains 1636 bp and an open reading frame of 1122 nucleotides capable of eneoding 373 amino acid polypeptides with a predicted molecular mass of 42.3 kda and pI of 6.01. The putative ZmSIMK1 protein contains all 11 conserved subdomains that are characteristics of serine/threonine protein kinases and the TEY motif, which is the putative phosphorylation site. Northern blot analysis shows that ZmSIMK1 is ubiquitously expressed in roots, stems, and leaves of maize seedlings and its mRNA accumulation is observed in maize seedlings treated with 30 mmol/L PEG-6000 and 137 mmol/L NaCl, but the expression of ZmSIMK1 is not significantly affected by 4℃ treatment. The expression vector pET-ZmSIMK1 is constructed by inserting the coding region of ZmSIMK1 eDNA into pET-42a(+), and transformed into E. coli strain BL21(DE3). A 77kda fusion protein is induced by the further culture at 37℃ after addition of 1 mmol/L IPTG.展开更多
文摘A new MAPK gene, ZmSIMK1 (Zea mays L. salt-induced mitogen-activated protein kinase 1), is isolatod from a maize eDNA library. The full-length ZmSIMK1 gene contains 1636 bp and an open reading frame of 1122 nucleotides capable of eneoding 373 amino acid polypeptides with a predicted molecular mass of 42.3 kda and pI of 6.01. The putative ZmSIMK1 protein contains all 11 conserved subdomains that are characteristics of serine/threonine protein kinases and the TEY motif, which is the putative phosphorylation site. Northern blot analysis shows that ZmSIMK1 is ubiquitously expressed in roots, stems, and leaves of maize seedlings and its mRNA accumulation is observed in maize seedlings treated with 30 mmol/L PEG-6000 and 137 mmol/L NaCl, but the expression of ZmSIMK1 is not significantly affected by 4℃ treatment. The expression vector pET-ZmSIMK1 is constructed by inserting the coding region of ZmSIMK1 eDNA into pET-42a(+), and transformed into E. coli strain BL21(DE3). A 77kda fusion protein is induced by the further culture at 37℃ after addition of 1 mmol/L IPTG.