Genomic evolution and complexity of the Anaphase-promoting Complex (APC) in land plants
1 Laboratório de Biologia Molecular de Plantas, Instituto de Bioquímica Médica, CCS, Cidade Universitária - Ilha do Fundão, CEP 21941-590, Rio de Janeiro, RJ, Brasil
2 Centro de Genômica e Fitomelhoramento, Departamento de Fitotecnia, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas, Campus Universitário s/n - Capão do Leão, CEP 90001-970, Pelotas, RS, Brasil
3 Stockholm Bioinformatics Center, Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, 106, 91,Stockholm, Sweden
BMC Plant Biology 2010, 10:254 doi:10.1186/1471-2229-10-254Published: 18 November 2010
The orderly progression through mitosis is regulated by the Anaphase-Promoting Complex (APC), a large multiprotein E3 ubiquitin ligase that targets key cell-cycle regulators for destruction by the 26 S proteasome. The APC is composed of at least 11 subunits and associates with additional regulatory activators during mitosis and interphase cycles. Despite extensive research on APC and activator functions in the cell cycle, only a few components have been functionally characterized in plants.
Here, we describe an in-depth search for APC subunits and activator genes in the Arabidopsis, rice and poplar genomes. Also, searches in other genomes that are not completely sequenced were performed. Phylogenetic analyses indicate that some APC subunits and activator genes have experienced gene duplication events in plants, in contrast to animals. Expression patterns of paralog subunits and activators in rice could indicate that this duplication, rather than complete redundancy, could reflect initial specialization steps. The absence of subunit APC7 from the genome of some green algae species and as well as from early metazoan lineages, could mean that APC7 is not required for APC function in unicellular organisms and it may be a result of duplication of another tetratricopeptide (TPR) subunit. Analyses of TPR evolution suggest that duplications of subunits started from the central domains.
The increased complexity of the APC gene structure, tied to the diversification of expression paths, suggests that land plants developed sophisticated mechanisms of APC regulation to cope with the sedentary life style and its associated environmental exposures.