Adenylate cyclase activity of TIR1/AFB auxin receptors in plants

Article

关键词: BOX PROTEIN TIR1;    VISUALIZATION;    EFFICIENT;    SOFTWARE;    FAMILY;    CAMP;   

DOI  :  10.1038/s41586-022-05369-7

来源: SCIE

【 摘 要 】

The phytohormone auxin is the major coordinative signal in plant development(1), mediating transcriptional reprogramming by a well-established canonical signalling pathway. TRANSPORT INHIBITOR RESPONSE 1 (TIR1)/AUXIN-SIGNALING F-BOX (AFB) auxin receptors are F-box subunits of ubiquitin ligase complexes. In response to auxin, they associate with Aux/IAA transcriptional repressors and target them for degradation via ubiquitination(2,3). Here we identify adenylate cyclase (AC) activity as an additional function of TIR1/AFB receptors across land plants. Auxin, together with Aux/IAAs, stimulates cAMP production. Three separate mutations in the AC motif of the TIR1 C-terminal region, all of which abolish the AC activity, each render TIR1 ineffective in mediating gravitropism and sustained auxin-induced root growth inhibition, and also affect auxin-induced transcriptional regulation. These results highlight the importance of TIR1/AFB AC activity in canonical auxin signalling. They also identify a unique phytohormone receptor cassette combining F-box and AC motifs, and the role of cAMP as a second messenger in plants.

【 授权许可】

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