InterPro domain: IPR044532

This entry include Protein BREVIS RADIX (BRX) and related proteins such as BRXL1-4 from plants. BRX has been identified through a natural loss-of-function allele in the Arabidopsis accession Umkirch-1 (Uk-1), and results in reduced root meristem size, reduced mature cell size, and thus reduced root growth [ 1 ]. BRX has been shown to regulate the growth rate in both the root and shoot. It mediates cross-talk between the auxin and brassinosteroid pathways [ 2 , 3 ].

Despite the protein sequence similarity between Arabidopsis BRXL proteins, analysis of brx brx-like multiple mutants indicates that functional redundancy of BRXLs is limited [ 4 ].

1. Natural genetic variation in Arabidopsis identifies BREVIS RADIX, a novel regulator of cell proliferation and elongation in the root. Genes Dev. 18, 700-14
2. BRX promotes Arabidopsis shoot growth. New Phytol. 188, 23-9
3. BRX mediates feedback between brassinosteroid levels and auxin signalling in root growth. Nature 443, 458-61
4. Characterization of the plant-specific BREVIS RADIX gene family reveals limited genetic redundancy despite high sequence conservation. Plant Physiol. 140, 1306-16