High impact information on CIPK1

• Mutation of conserved residues either abolished or significantly diminished the affinity of AtCIPK1 for AtCBL2 [1].
• Physical interaction of CIPK1 with CBL1 and CBL9 targets the kinase to the plasma membrane [2].
• We therefore suggest that, by alternative complex formation with either CBL1 or CBL9, the kinase CIPK1 represents a convergence point for ABA-dependent and ABA-independent stress responses [2].
• Alternative complex formation of the Ca-regulated protein kinase CIPK1 controls abscisic acid-dependent and independent stress responses in Arabidopsis [2].
• Remarkably, in contrast to the cbl1 mutant and similarly to the cbl9 mutant, loss of CIPK1 function impairs abscisic acid (ABA) responsiveness [2].

Biological context of CIPK1

• Calcium sensors and their interacting protein kinases: genomics of the Arabidopsis and rice CBL-CIPK signaling networks [3].
• These findings suggest that the CBL/CIPK or SCaBP/PKS signaling pathways recently found in Arabidopsis may also exist in rice and function in cold response in which calcium signal serves as a second messenger [4].

Physical interactions of CIPK1

• The studies on calcium sensor calcineurin B-like protein (CBL) and CBL interacting protein kinases (CIPK) are limited to Arabidopsis and rice and their functional role is only beginning to emerge [5].

Other interactions of CIPK1

• We show that, similarly to loss of CBL9 function, mutation of either CBL1 or CIPK1 renders plants hypersensitive to osmotic stress [2].
• OsCK1 actually interacts with AtCBL3 through the C-terminal region in a yeast two-hybrid system, suggesting that OsCK1 is probably a rice orthologue of one of the CIPK/PKS members [4].

References