Cyclin D1 and p22ack1 play opposite roles in plant growth and development.
The plant cell division cycle, a highly coordinated process, is continually regulated during the growth and development of plants. In this report, we demonstrate how two cell-cycle regulators act together to control cell proliferation in transgenic Arabidopsis. To identify potential cyclin dependent kinase regulators from Arabidopsis, we employed an two-hybrid screening system to isolate genes encoding G1 specific cyclin-interacting proteins. One of these, p22(ack1), which encodes a novel 22kDa protein, binds to cyclin D1. Overexpression of p22(ack1) in transgenic Arabidopsis resulted in growth retardation due to a strong inhibition of cell division in the leaf primordial and meristematic tissue. The leaf shape of p22(ack1) transgenic Arabidopsis was altered from oval in wild-type to dentate. Wild-type phenotype was successfully restored in F1 hybrids by cross-hybridizing the p22(ackl)Arabidopsis mutants with cyclin D1. Taken together, these results suggest that p22(ack1) and cyclin D1, which act antagonistically, are major rate-limiting factors for cell division in the leaf meristem.
Kumho Life and Environmental Science Laboratory, Oryongdong, Bukgu, Kwangju 500-712, Republic of Korea.
Jeong Woo
JW
Cho
Sun Chung
SC
Park
Eun Ah
EA
Shin
Chong Ki
CK
Kim
Woong
W
Han
Soo-In
SI
Sohn
Pill Soon
PS
Song
Myeong Hyeon
MH
Wang
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D019938:Cyclin D1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D018519:Meristem / Q000166:cytology / Q000378:metabolism; D010641:Phenotype; D018515:Plant Leaves / Q000033:anatomy & histology; D030821:Plants, Genetically Modified; D020798:Two-Hybrid System Techniques
D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; C494427:p22ack1 protein, Arabidopsis; D019938:Cyclin D1