Work

The Arabidopsis SOS2 protein kinase physically interacts with and is activated by the calcium-binding protein SOS3

Year: 2000

Type: article

Abstract: The Arabidopsis thaliana SOS2 and SOS3 genes are required for intracellular Na(+) and K(+) homeostasis and plant tolerance to high Na(+) and low K(+) environments. SOS3 is an EF hand type calcium-binding protein having sequence similarities with animal neuronal calcium sensors and the yeast calcineurin B. SOS2 is a serine/threonine protein kinase in the SNF1/AMPK family. We report here that SOS3 physically interacts with and activates SOS2 protein kinase. Genetically, sos2sos3 double mutant analysis indicates that SOS2 and SOS3 function in the same pathway. Biochemically, SOS2 interacts with SOS3 in the yeast two-hybrid system and in vitro binding assays. The interaction is mediated by the C-terminal regulatory domain of SOS2. SOS3 activates SOS2 protein kinase activity in a Ca(2+)-dependent manner. Therefore, SOS3 and SOS2 define a novel regulatory pathway important for the control of intracellular ion homeostasis and salt tolerance in plants.

Source: Proceedings of the National Academy of Sciences

DOI: 10.1073/pnas.97.7.3735

Authors: Ursula Halfter, Manabu Ishitani, Jian-Kang Zhu

Institutions: University of Arizona, Carnegie Institution for Science

Language: English

Topic: Plant Stress Responses and Tolerance

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: green

Funders: U.S. Department of Agriculture, National Institutes of Health, National Institute of General Medical Sciences