To investigate the specialization of the two Arabidopsis CDC27 subunits in the anaphase-promoting complex (APC/C), we analyzed novel alleles of HBT/CDC27B and CDC27A, and characterized the expression of complementing HOBBIT (HBT) protein fusions in plant meristems and during the cell cycle. In contrast to other APC/C mutants, which are gametophytic lethal, phenotypes of weak and null hbt alleles indicate a primary role in the control of post-embryonic cell division and cell elongation, whereas cdc27a nulls are phenotypically indistinguishable from the wild type. However, cdc27a hbt double-mutant gametes are non-viable, indicating a redundant requirement for both CDC27 subunits during gametogenesis. Yeast-two-hybrid and pulldown studies with APC/C components suggest that the two Arabidopsis CDC27 subunits participate in several complexes that are differentially required during plant development. Loss-of-function analysis, as well as cyclin B reporter protein accumulation, indicates a conserved role for the plant APC/C in controlling mitotic progression and cell differentiation during the entire life cycle.
Perez-Perez, J., Serralbo, O., Vanstraelen, M., Gonzalez, C., Criqui, M-C., Genschik, P., Kondorosi, E., & Scheres, B. (2008). Specialization of CDC27 function in the Arabidopsis thaliana anaphase-promoting complex (APC/C). The Plant Journal, 53(1), 78 - 89. https://doi.org/10.1111/j.1365-313X.2007.03312.x