Disease relevance of CCD7

• To determine the biochemical function of AtCCD7, the protein was expressed in carotenoid-accumulating strains of Escherichia coli [1].

High impact information on CCD7

• Among these, auxin, moving down the plant in the main stem, indirectly inhibits axillary bud outgrowth, and an as yet undefined hormone, the synthesis of which in Arabidopsis requires MAX1, MAX3, and MAX4, moves up the plant and also inhibits shoot branching [2].
• MAX3/CCD7 is a carotenoid cleavage dioxygenase required for the synthesis of a novel plant signaling molecule [3].
• It was shown that the recombinant AtCCD7 protein catalyzes a specific 9-10 cleavage of beta-carotene to produce the 10 black triangle down-apo-beta-carotenal (C27) and beta-ionone (C13) [1].
• The rescue of the Arabidopsis max3 mutant phenotype by the introduction of Pro(35S):HTD1 indicates HTD1 is a carotenoid cleavage dioxygenase that has the same function as MAX3 in synthesis of a carotenoid-derived signal molecule [4].
• These roles for MAX3, MAX4, and MAX2 are consistent with their known molecular identities [5].

Chemical compound and disease context of CCD7

• When AtCCD7 and AtCCD8 were co-expressed in a beta-carotene-producing strain of E. coli, the 13-apo-beta-carotenone (C18) was produced [1].

Biological context of CCD7

• Unlike ccd7/max3 and ccd8/max4, both characterized as having highly branched phenotypes, ccd1 loss-of-function mutants are indistinguishable from wild-type plants [6].

Associations of CCD7 with chemical compounds

• The sequential cleavages of beta-carotene by AtCCD7 and AtCCD8 are likely the initial steps in the synthesis of a carotenoid-derived signaling molecule that is necessary for the regulation lateral branching [1].

Other interactions of CCD7

• Thus, even though CCD1 has similar enzymatic activity to CCD7/MAX3, it does not have a role in synthesis of the lateral shoot growth inhibitor [6].

References