High impact information on CAB1

• We have identified and partially purified a DNA binding protein from Arabidopsis that interacts specifically with the phytochrome-responsive promoter of the Arabidopsis cab140 gene [1].
• This mutant, named lct for low level of cab140 transcript, was obtained during a selection for phytochrome signal transduction mutants [2].
• Furthermore, the lct phenotype could not be separated genetically from the T-DNA insert; thus, we suggest that this phenotype was caused by cosuppression of the introduced construct and the endogenous cab140 gene, and that the mutation causing the cosuppression was located on the T-DNA insert [2].
• Further, 1.34 kilobases of the cab1 promoter was sufficient to confer this expression pattern on a reporter gene in transgenic Arabidopsis seedlings [3].
• We studied cis regulatory elements controlling the light-dependent organ-specific expression of Arabidopsis thaliana chlorophyll a/b binding protein gene (cab1) by stably transforming tobacco plants using a tumor-inducing (Ti) plasmid vector system [4].

Biological context of CAB1

• This aspect of cab gene expression differs from the strain Columbia of A. thaliana in which AB140 mRNA is the predominant message [5].
• Expression analysis by quantitative reverse transcription-PCR in transgenic plants showed up-regulation of the ABI4 and CAB1 genes [6].
• Mobility shift assays were performed to identify a nuclear protein factor and its binding sites on the cab1 promoter [7].

Other interactions of CAB1

• Furthermore, similar to the CAB1 promoter, a Z-GATA containing promoter is derepressed in cop1 mutants in the dark [8].

Analytical, diagnostic and therapeutic context of CAB1

• To identify the binding sites that are involved in the light responsiveness, mobility shift assays were performed between the cab1 promoter fragments and the nuclear extracts prepared from the 2 day dark-adapted sample [7].

References