Mapping and engineering of auxin-induced plasma membrane dissociation in BRX family proteins.
Plant Cell
; 33(6): 1945-1960, 2021 07 19.
Article
en En
| MEDLINE
| ID: mdl-33751121
ABSTRACT
Angiosperms have evolved the phloem for the long-distance transport of metabolites. The complex process of phloem development involves genes that only occur in vascular plant lineages. For example, in Arabidopsis thaliana, the BREVIS RADIX (BRX) gene is required for continuous root protophloem differentiation, together with PROTEIN KINASE ASSOCIATED WITH BRX (PAX). BRX and its BRX-LIKE (BRXL) homologs are composed of four highly conserved domains including the signature tandem BRX domains that are separated by variable spacers. Nevertheless, BRX family proteins have functionally diverged. For instance, BRXL2 can only partially replace BRX in the root protophloem. This divergence is reflected in physiologically relevant differences in protein behavior, such as auxin-induced plasma membrane dissociation of BRX, which is not observed for BRXL2. Here we dissected the differential functions of BRX family proteins using a set of amino acid substitutions and domain swaps. Our data suggest that the plasma membrane-associated tandem BRX domains are both necessary and sufficient to convey the biological outputs of BRX function and therefore constitute an important regulatory entity. Moreover, PAX target phosphosites in the linker between the two BRX domains mediate the auxin-induced plasma membrane dissociation. Engineering these sites into BRXL2 renders this modified protein auxin-responsive and thereby increases its biological activity in the root protophloem context.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Arabidopsis
/
Proteínas de Arabidopsis
/
Ácidos Indolacéticos
Límite:
Animals
Idioma:
En
Revista:
Plant Cell
Asunto de la revista:
BOTANICA
Año:
2021
Tipo del documento:
Article
País de afiliación:
Suiza