SCABP8/CBL10, a putative calcium sensor, interacts with the protein kinase SOS2 to protect Arabidopsis shoots from salt stress
SCABP8/CBL10, a putative calcium sensor, interacts with the protein kinase SOS2 to protect Arabidopsis shoots from salt stress
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DOI：
10.1105/tpc.106.042291
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发表时间：
2007-04-01
期刊：
影响因子：
11.6
通讯作者：
Guo, Yan
中科院分区：
文献类型：
--
作者：
Quan, Ruidang;Lin, Huixin;Guo, Yan
SOS（Salt Overly Sensitive）信号通路在拟南芥的耐盐性中起着重要的作用。在盐胁迫下，钙传感器SOS 3激活激酶SOS 2，该激酶SOS 2正向调节细胞膜钠/质子逆向转运蛋白SOS 1。我们发现，SOS 3的行为主要是在盐胁迫下的根。相比之下，SOS 3同源物SOS 3样钙结合蛋白8（SCABP 8）/钙神经磷酸酶B-LIKE 10主要在芽对盐毒性的反应中起作用。而根生长减少在sos 3突变体在NaCl的存在下，盐敏感性scabp 8是更突出的地上部组织。SCABP 8进一步显示结合钙，在体外和体内与SOS 2相互作用，将SOS 2募集到质膜，以钙依赖性方式增强SOS 2活性，并激活酵母中的SOS 1。此外，sos 3 scabp 8和sos 2 scabp 8显示出与sos 2相似的表型，其对盐的敏感性高于单独的sos 3或scabp 8。SCABP 8在sos 3中的过表达部分挽救了sos 3盐敏感表型。然而，S 0 S3的过表达不能补充scabp 8。这些结果表明，SCABP 8和SOS 3在其功能上仅部分冗余，并且各自在植物盐胁迫响应中发挥额外且独特的作用。
The SOS (for Salt Overly Sensitive) pathway plays essential roles in conferring salt tolerance in Arabidopsis thaliana. Under salt stress, the calcium sensor SOS3 activates the kinase SOS2 that positively regulates SOS1, a plasma membrane sodium/proton antiporter. We show that SOS3 acts primarily in roots under salt stress. By contrast, the SOS3 homolog SOS3-LIKE CALCIUM BINDING PROTEIN8 (SCABP8)/CALCINEURIN B-LIKE10 functions mainly in the shoot response to salt toxicity. While root growth is reduced in sos3 mutants in the presence of NaCl, the salt sensitivity of scabp8 is more prominent in shoot tissues. SCABP8 is further shown to bind calcium, interact with SOS2 both in vitro and in vivo, recruit SOS2 to the plasma membrane, enhance SOS2 activity in a calcium-dependent manner, and activate SOS1 in yeast. In addition, sos3 scabp8 and sos2 scabp8 display a phenotype similar to sos2, which is more sensitive to salt than either sos3 or scabp8 alone. Overexpression of SCABP8 in sos3 partially rescues the sos3 salt-sensitive phenotype. However, overexpression of SOS3 fails to complement scabp8. These results suggest that SCABP8 and SOS3 are only partially redundant in their function, and each plays additional and unique roles in the plant salt stress response.