Chimeric calcium/calmodulin-dependent protein kinase in tobacco: differential regulation by calmodulin isoforms
Chimeric calcium/calmodulin-dependent protein kinase in tobacco: differential regulation by calmodulin isoforms
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DOI：
10.1023/a:1006019001200
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发表时间：
1998-11
影响因子：
5.1
通讯作者：
Zhihua Liu-;M. Xia;B. Poovaiah
中科院分区：
文献类型：
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作者：
Zhihua Liu-;M. Xia;B. Poovaiah
从烟草中分离并鉴定了嵌合钙/钙调素依赖性蛋白激酶（CCaMK）的cDNA克隆（TCCaMK-1和TCCaMK-2）。由TCCaMK-1和TCCaMK-2编码的多肽具有15个不同的氨基酸取代，但它们都含有总共517个氨基酸。北方分析表明，CCaMK在花药发育过程中以阶段特异性方式表达。在0.5 ~ 1.0cm的芽长范围内均能检测到mRNA。mRNA的出现与减数分裂相一致，在花药发育的后期变得不可检测。利用同工型特异性引物进行的逆转录聚合酶链反应（RT-PCR）扩增分析表明，两种CCaMK mRNA在花药中以相似的表达模式表达。在大肠杆菌中表达的CCaMK蛋白表现出Ca 2+依赖的自磷酸化和Ca 2 +/钙调素依赖的底物磷酸化。钙调素异构体（PCM 1和PCM 6）对烟草CCaMK的自磷酸化和底物磷酸化的调节具有不同的作用，但对百合CCaMK没有影响。植物丝氨酸/苏氨酸蛋白激酶的进化树表明，钙调素依赖性激酶形成一个亚群，明显不同于钙依赖性蛋白激酶（CDPKs）和其他丝氨酸/苏氨酸激酶在植物中。
cDNA clones of chimeric Ca2+/calmodulin-dependent protein kinase (CCaMK) from tobacco (TCCaMK-1 and TCCaMK-2) were isolated and characterized. The polypeptides encoded by TCCaMK-1 and TCCaMK-2 have 15 different amino acid substitutions, yet they both contain a total of 517 amino acids. Northern analysis revealed that CCaMK is expressed in a stage-specific manner during anther development. Messenger RNA was detected when tobacco bud sizes were between 0.5 cm and 1.0 cm. The appearance of mRNA coincided with meiosis and became undetectable at later stages of anther development. The reverse polymerase chain reaction (RT-PCR) amplification assay using isoform-specific primers showed that both of the CCaMK mRNAs were expressed in anther with similar expression patterns. The CCaMK protein expressed in Escherichia coli showed Ca2+-dependent autophosphorylation and Ca2+/calmodulin-dependent substrate phosphorylation. Calmodulin isoforms (PCM1 and PCM6) had differential effects on the regulation of autophosphorylation and substrate phosphorylation of tobacco CCaMK, but not lily CCaMK. The evolutionary tree of plant serine/threonine protein kinases revealed that calmodulin-dependent kinases form one subgroup that is distinctly different from Ca2+-dependent protein kinases (CDPKs) and other serine/threonine kinases in plants.