甘蓝自交不亲和性信号传导元件与传导过程
, 周燕 Protein Elements and Signal Transduction Process of Self-Incompatibility in Brassica oleracea
ZHU Li-Quan, ZHOU Yan
, ZHOU Yan Fig. 4 Brassica oleracea L. self-incompatible molecular process that papilla cell rejects self-pollen In the absence of SCR, SRK binds to the same haplotype SRK, forming SRK-SRK dimer; the protein ARC1 shuttles between the nucleas and cytoplasm. In the presence of self-pollen, SCR, released from the pollen coat, binds to and actives SRK, causing the dimer depolymerized, SRK then phosphorylatesP itself and in a moment phosphorylates MLPK, the two phosphorylated moleculars then both interactive with the C terminal of ARC1, ARM, made ARC1 phosphorylated and activated, changing location from nucleus to membrane [ 60 ] , at the same time, ARC1 N terminal attaches to Exo70A1, by the means of Ub-activation enzymes, E1, and Ub-conjugating enzymes, E2, Exo70A1 be ubiquitined by several Ubs, then ARC1 U-box leads this Exo70A1 to 26S proteasome [ 71 ] and be degraded, as the lever of Exo70A1 protein lower some threshold value causes the MOD and MIP-MOD closing, preventing water and other material from being delivered to the pollen, inhibiting the development of pollen tube and the germination of self pollen, that is the essential display of SI reaction.
