TableEdit

Kim, J and Kim, HY (2006) Functional analysis of a calcium-binding transcription factor involved in plant salt stress signaling. FEBS Lett. 580:5251-6

Calcium is known to serve as a secondary messenger to mediate salt stress signaling pathway. We found a calcium-binding basic/helix-loop-helix-type transcription factor (AtNIG1) as a salt stress-responsive gene by using the suppression subtractive hybridization. The AtNIG1 was targeted into nucleus and bound to (45)Ca(2+), suggesting that AtNIG1 is a nuclear calcium-binding protein. In addition, AtNIG1 bound specifically to the E-box-DNA sequence (CANNTG), which is found in the promoter regions of many salt stress-related genes. Functional analyses with an atnig1-1 knockout mutant revealed that the mutant plants show enhanced sensitivity to salt stress. Further analyses indicated that the atnig1-1 plants have reduced survival rate, fresh weight, chlorophyll content, and protein content upon salt stress, suggesting that the AtNIG1 plays a critical role in plant salt stress signaling. Therefore, this study represents that AtNIG1 is the first known calcium-binding transcription factor involved in plant salt stress signaling.

PubMed Online version:10.1016/j.febslet.2006.08.050

Active Transport, Cell Nucleus/drug effects; Active Transport, Cell Nucleus/genetics; Amino Acid Sequence; Arabidopsis/genetics; Arabidopsis/metabolism; Arabidopsis Proteins/genetics; Arabidopsis Proteins/metabolism; Basic Helix-Loop-Helix Transcription Factors/genetics; Basic Helix-Loop-Helix Transcription Factors/metabolism; Calcium/metabolism; Calcium-Binding Proteins/genetics; Calcium-Binding Proteins/metabolism; Cell Nucleus/genetics; Cell Nucleus/metabolism; Molecular Sequence Data; Plants, Genetically Modified/genetics; Plants, Genetically Modified/metabolism; Protein Binding/drug effects; Protein Binding/genetics; Signal Transduction/drug effects; Signal Transduction/genetics; Sodium Chloride/pharmacology