Phosphorylation of synthetic peptides by a CDPK and plant SNF1-related protein kinase. Influence of proline and basic amino acid residues at selected positions
Phosphorylation of synthetic peptides by a CDPK and plant SNF1-related protein kinase. Influence of proline and basic amino acid residues at selected positions
复制标题
DOI：
10.1093/pcp/pce137
复制
发表时间：
2001-10-01
影响因子：
4.9
通讯作者：
Huber, SC
中科院分区：
文献类型：
--
作者：
Huang, JZ;Huber, SC
菠菜（Spinacia oleracea L.）叶蔗糖磷酸合酶（SPS）可以通过钙调素样结构域蛋白激酶（CDPKs）或SNF 1相关蛋白激酶（SnRK 1）在体外磷酸化Ser-158而失活。虽然磷酸化位点序列是相对保守的，但大多数推导的双子叶植物SPS序列在Ser-158调节磷酸化位点周围含有P-4处的Pro残基（其中P是磷酸化的Ser）;菠菜是例外，在P-4处含有Arg。我们表明，在P-4的Pro选择性地抑制磷酸化的肽的CDPK相对于SnRK 1。在P-4的Pro的存在，通过允许在肽底物中的紧密转向，可能干扰在P-5和更远的残基的适当结合。这两种激酶对在P-6和P+5处具有碱性残基的肽具有更大的活性（除了已知的在P-3/P-4处需要Arg之外），并且当在P-6处的残基是His时，肽磷酸化的最佳pH发生酸移。这些结果用于预测可能被SnRK 1 s（而不是CDPKs）选择性磷酸化的蛋白质，例如双子叶植物物种中的SPS，或者可能以pH依赖性方式磷酸化。
Spinach (Spinacia oleracea L.) leaf sucrose-phosphate synthase (SPS) can be inactivated by phosphorylation of Ser-158 by calmodulin-like domain protein kinases (CDPKs) or SNF1-related protein kinases (SnRK1) in vitro. While the phosphorylation site sequence is relatively conserved, most of the deduced sequences of SPS from dicot species surrounding the Ser-158 regulatory phosphorylation site contain a Pro residue at P-4 (where P is the phosphorylated Ser); spinach is the exception and contains an Arg at P-4. We show that a Pro at P-4 selectively inhibits phosphorylation of the peptide by a CDPK relative to a SnRK1. The presence of a Pro at P-4, by allowing a tight turn in the peptide substrate, may interfere with proper binding of residues at P-5 and beyond. Both kinases had greater activity with peptides having basic residues at P-6 and P+5 (in addition to the known requirement for an Arg at P-3/P-4), and when the residue at P-6 was a His, the pH optimum for phosphorylation of the peptide was acid shifted. The results are used to predict proteins that may be selectively phosphorylated by SnRK1s (as opposed to CDPKs), such as SPS in dicot species, or may be phosphorylated in a pH-dependent manner.