533 / 2019-03-13 09:14:16

SUD6, a cyclin-dependent kinase, interacts with DA3 and CDKB1;1 to regulate endoreduplication and organ growth in Arabidopsis

endoreduplication,phosphorylation,organ growth,DA3/UBP14,CDKB1;1

全体主题 > Cell Biology

Endoreduplication is often correlated with cell and organ growth in animals and plants, but the genetic and molecular mechanisms that link endoreduplication with cell and organ growth are largely elusive. We have previously described that UBP14 (UBIQUITIN-SPECIFIC PROTEASE 14), encoded by the DA3 gene, interacts with UVI4 (ULTRAVIOLET-B INSENSITIVE4), an inhibitor of the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase, to regulate endoreduplication as well as cell and organ growth in Arabidopsis. The da3-1 mutant shows large cotyledons, leaves, and flowers with higher ploidy levels. Here, we report a cyclin-dependent kinase, encoded by the suppressor of da3-1 (SUD6), which associates with DA3 in vitro and in vivo. The mutant allele sud6-1 partially suppresses the da3-1 mutant phenotypes, indicating that SUD6 may act in a common pathway with DA3 to regulate endoreduplication. Further results reveal that SUD6 physically associates with cyclin-dependent kinase B1;1 (CDKB1;1), a downstream component of the APC/C. sud6-1 also suppresses the endoreplication level of CDKB1;1.N161. Thus, our findings establish a new genetic and molecular framework for the regulation of endoreduplication and organ growth.