Cold-Induced Changes in Freezing Tolerance, Protein Phosphorylation, and Gene Expression (Evidence for a Role of Calcium)
Cold-Induced Changes in Freezing Tolerance, Protein Phosphorylation, and Gene Expression (Evidence for a Role of Calcium)
复制标题
DOI：
10.1104/pp.102.4.1227
复制
发表时间：
1993-08
期刊：
影响因子：
--
通讯作者：
Antonio F. Monroy;F. Sarhan;R. Dhindsa
中科院分区：
文献类型：
--
作者：
Antonio F. Monroy;F. Sarhan;R. Dhindsa
在耐冷冻苜蓿品种（Medicago sativa spp. falcata cv Anik）的细胞悬浮培养物中，研究了 Ca2+ 在寒冷诱导的蛋白质磷酸化、基因表达和耐冷冻性发展变化中的作用。阻断 Ca2+ 通道、拮抗钙调蛋白作用或抑制蛋白激酶的化学处理显着抑制细胞发展寒冷诱导的冷冻耐受性的能力，但对细胞活力几乎没有影响。通过二维聚丙烯酰胺凝胶电泳对磷蛋白谱进行分析表明，在低温下，几种蛋白质的磷酸化相对水平增加，而其他几种蛋白质的磷酸化相对水平下降。当在钙调蛋白和Ca2+依赖性蛋白激酶拮抗剂N-(6-氨基己基)-5-氯-1-萘磺酰胺盐酸盐或Ca2+通道阻滞剂La3+存在下进行冷驯化时，冷诱导的蛋白质磷酸化变化被强烈抑制，细胞失去了产生冷冻耐受性的能力，并且冷驯化特异性基因转录物的积累显着减少。蛋白激酶抑制剂 1-(5-异喹啉磺酰基)-2-甲基哌嗪二盐酸盐对寒冷诱导的蛋白质磷酸化作用不太明显，并且仅部分抑制寒冷诱导的冷冻耐受性的发展和转录物的积累。一种约 15 kD 的蛋白质的磷酸化水平在低温下增加了 10 倍以上，并且与寒冷诱导的冷冻耐受性和基因表达呈强烈的正相关，即使后者被各种化学处理改变。这些结果表明，Ca2+ 和蛋白质磷酸化，或者可能是两者的耦合，在冷驯化过程中获得冷冻耐受性中发挥着重要作用。
The role of Ca2+ in cold-induced changes in protein phosphorylation, gene expression, and development of freezing tolerance has been studied in cell-suspension cultures of a freezing-tolerant cultivar of alfalfa (Medicago sativa spp. falcata cv Anik). Chemical treatments to block Ca2+ channels, antagonize calmodulin action, or inhibit protein kinases markedly inhibited the cellular capacity to develop cold-induced freezing tolerance but had little effect on cell viability. An analysis of phosphoprotein profile by two-dimensional polyacrylamide gel electrophoresis revealed that at low temperature the relative level of phosphorylation of several proteins increased, whereas that of several others decreased. When cold acclimation was carried out in the presence of N-(6-aminohexyl)-5-chloro-1-naphthalene-sulfonamide hydrochloride, an antagonist of calmodulin and Ca2+-dependent protein kinases, or the Ca2+ channel blocker La3+, the cold-induced changes in protein phosphorylation were strongly inhibited, cells lost their capacity to develop freezing tolerance, and accumulation of transcripts of cold acclimation-specific genes was substantially reduced. An inhibitor of protein kinases, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride, had less pronounced effects on the cold-induced protein phosphorylation and caused only a partial inhibition of the cold-induced development of freezing tolerance and accumulation of the transcripts. The level of phosphorylation of one protein, of about 15 kD, increased more than 10-fold at low temperature and showed a strong positive correlation with cold-induced freezing tolerance and gene expression even when the latter were altered with various chemical treatments. These results suggest that Ca2+ and protein phosphorylation, or perhaps a coupling of the two, play an important role during the acquisition of freezing tolerance during cold acclimation.