Activation of an alfalfa cyclin-dependent kinase inhibitor by calmodulin-like domain protein kinase.
Pettko-Szandtner, A., Meszaros, T., Horvath, G. V., Bakó, L., Csordas-Toth, E., Blastyak, A., Zhiponova, M., Miskolczi, P., & Dudits, D.
Plant Journal, 46(1): 111–123. April 2006.
Place: Hoboken Publisher: Wiley WOS:000236035700008
doi
link
bibtex
abstract
@article{pettko-szandtner_activation_2006,
title = {Activation of an alfalfa cyclin-dependent kinase inhibitor by calmodulin-like domain protein kinase},
volume = {46},
issn = {0960-7412},
doi = {10/b4vt9r},
abstract = {Kip- related proteins ( KRPs) play a central role in the regulation of the cell cycle and differentiation through modulation of cyclin- dependent kinase ( CDK) functions. We have identified a CDK inhibitor gene from Medicago truncatula ( Mt) by a yeast two- hybrid screen. The KRPMt gene was expressed in all plant organs and cultured cells, and its transcripts accumulated after abscisic acid and NaCl treatment. The KRPMt protein exhibits seven conserved sequence domains and a PEST motif that is also detected in various Arabidopsis KRPs. In the yeast two- hybrid test, the KRPMt protein interacted with CDK ( Medsa; CDKA; 1) and D- type cyclins. However, in the pull- down assays, B- type CDK complexes were also detectable. Recombinant KRPMt differentially inhibited various alfalfa CDK complexes in phosphorylation assays. The immunoprecipitated Medsa; CDKA; 1/ A; 2 complex was strongly inhibited, whereas the mitotic Medsa; CDKB2; 1 complex was the most sensitive to inhibition. Function of Medsa; CDKB1; 1 complex was not inhibited by the KRPMt protein. The mitotic Medsa; CYCB2 and Medsa; CYCA2; 1 complexes responded weakly to this inhibitor protein. Kinase complexes from G2/ M cells showed increased sensitivity towards the inhibitor compared with those isolated from G1/ S- phase cells. In vitro phosphorylation of Medicago retinoblastoma- related protein was also reduced in the presence of KRPMt. Phosphorylation of this inhibitor protein by the recombinant calmodulin- like domain protein kinase ( MsCPK3) resulted in enhanced inhibition of CDK function. The data presented emphasize the selective sensitivity of various cyclin- dependent kinase complexes to this inhibitor protein, and suggest a role for CDK inhibitors and CPKs in cross- talk between Ca2+ signalling and regulation of cell- cycle progression in plants.},
language = {English},
number = {1},
journal = {Plant Journal},
author = {Pettko-Szandtner, A. and Meszaros, T. and Horvath, G. V. and Bakó, L. and Csordas-Toth, E. and Blastyak, A. and Zhiponova, M. and Miskolczi, P. and Dudits, D.},
month = apr,
year = {2006},
note = {Place: Hoboken
Publisher: Wiley
WOS:000236035700008},
keywords = {Ca2+ signalling, abscisic acid, arabidopsis-thaliana, calcium, cell cycle, cyclin-dependent kinase, expression, gene family, ick1, in-vitro, medicago-sativa, phosphorylation, plant-cell cycle, retinoblastoma-related protein},
pages = {111--123},
}
Kip- related proteins ( KRPs) play a central role in the regulation of the cell cycle and differentiation through modulation of cyclin- dependent kinase ( CDK) functions. We have identified a CDK inhibitor gene from Medicago truncatula ( Mt) by a yeast two- hybrid screen. The KRPMt gene was expressed in all plant organs and cultured cells, and its transcripts accumulated after abscisic acid and NaCl treatment. The KRPMt protein exhibits seven conserved sequence domains and a PEST motif that is also detected in various Arabidopsis KRPs. In the yeast two- hybrid test, the KRPMt protein interacted with CDK ( Medsa; CDKA; 1) and D- type cyclins. However, in the pull- down assays, B- type CDK complexes were also detectable. Recombinant KRPMt differentially inhibited various alfalfa CDK complexes in phosphorylation assays. The immunoprecipitated Medsa; CDKA; 1/ A; 2 complex was strongly inhibited, whereas the mitotic Medsa; CDKB2; 1 complex was the most sensitive to inhibition. Function of Medsa; CDKB1; 1 complex was not inhibited by the KRPMt protein. The mitotic Medsa; CYCB2 and Medsa; CYCA2; 1 complexes responded weakly to this inhibitor protein. Kinase complexes from G2/ M cells showed increased sensitivity towards the inhibitor compared with those isolated from G1/ S- phase cells. In vitro phosphorylation of Medicago retinoblastoma- related protein was also reduced in the presence of KRPMt. Phosphorylation of this inhibitor protein by the recombinant calmodulin- like domain protein kinase ( MsCPK3) resulted in enhanced inhibition of CDK function. The data presented emphasize the selective sensitivity of various cyclin- dependent kinase complexes to this inhibitor protein, and suggest a role for CDK inhibitors and CPKs in cross- talk between Ca2+ signalling and regulation of cell- cycle progression in plants.
EBP1 regulates organ size through cell growth and proliferation in plants.
Horváth, B. M, Magyar, Z., Zhang, Y., Hamburger, A. W, Bakó, L., Visser, R. G., Bachem, C. W., & Bögre, L.
The EMBO Journal, 25(20): 4909–4920. October 2006.
Publisher: John Wiley & Sons, Ltd
![EBP1 regulates organ size through cell growth and proliferation in plants [link]](//bibbase.org/img/filetypes/link.svg "Paper")
Paper
doi
link
bibtex
abstract
@article{horvath_ebp1_2006,
title = {{EBP1} regulates organ size through cell growth and proliferation in plants},
volume = {25},
issn = {0261-4189},
url = {https://www.embopress.org/doi/full/10.1038/sj.emboj.7601362},
doi = {10.1038/sj.emboj.7601362},
abstract = {Plant organ size shows remarkable uniformity within species indicating strong endogenous control. We have identified a plant growth regulatory gene, functionally and structurally homologous to human EBP1. Plant EBP1 levels are tightly regulated; gene expression is highest in developing organs and correlates with genes involved in ribosome biogenesis and function. EBP1 protein is stabilised by auxin. Elevating or decreasing EBP1 levels in transgenic plants results in a dose-dependent increase or reduction in organ growth, respectively. During early stages of organ development, EBP1 promotes cell proliferation, influences cell-size threshold for division and shortens the period of meristematic activity. In postmitotic cells, it enhances cell expansion. EBP1 is required for expression of cell cycle genes; CyclinD3;1, ribonucleotide reductase 2 and the cyclin-dependent kinase B1;1. The regulation of these genes by EBP1 is dose and auxin dependent and might rely on the effect of EBP1 to reduce RBR1 protein level. We argue that EBP1 is a conserved, dose-dependent regulator of cell growth that is connected to meristematic competence and cell proliferation via regulation of RBR1 level.},
number = {20},
urldate = {2021-06-11},
journal = {The EMBO Journal},
author = {Horváth, Beatrix M and Magyar, Zoltán and Zhang, Yuexing and Hamburger, Anne W and Bakó, László and Visser, Richard GF and Bachem, Christian WB and Bögre, László},
month = oct,
year = {2006},
note = {Publisher: John Wiley \& Sons, Ltd},
keywords = {EBP1, arabidopsis, cell growth, cell proliferation, cycle regulation, differential gene-expression, division, ebp1, erbb-3 binding-protein, expansion, leaf, organ growth, organogenesis, potato-tuber development, ribosome biogenesis, transcription factor},
pages = {4909--4920},
}
Plant organ size shows remarkable uniformity within species indicating strong endogenous control. We have identified a plant growth regulatory gene, functionally and structurally homologous to human EBP1. Plant EBP1 levels are tightly regulated; gene expression is highest in developing organs and correlates with genes involved in ribosome biogenesis and function. EBP1 protein is stabilised by auxin. Elevating or decreasing EBP1 levels in transgenic plants results in a dose-dependent increase or reduction in organ growth, respectively. During early stages of organ development, EBP1 promotes cell proliferation, influences cell-size threshold for division and shortens the period of meristematic activity. In postmitotic cells, it enhances cell expansion. EBP1 is required for expression of cell cycle genes; CyclinD3;1, ribonucleotide reductase 2 and the cyclin-dependent kinase B1;1. The regulation of these genes by EBP1 is dose and auxin dependent and might rely on the effect of EBP1 to reduce RBR1 protein level. We argue that EBP1 is a conserved, dose-dependent regulator of cell growth that is connected to meristematic competence and cell proliferation via regulation of RBR1 level.
In many dicot plants lateral roots arise from a dedicated cell file of the main root called pericycle. Initiation of lateral roots requires the phytohormone auxin that first triggers critical asymmetric cell divisions in the pericycle then acts as an instructive signal for lateral root growth and development. 
Expression of RBR-RFP fusion protein in Arabidopsis root after treatment with the auxins 2,4-D (left) or NAA (right).
![ZEITLUPE Promotes ABA-Induced Stomatal Closure in Arabidopsis and Populus [link]](http://bibbase.org/img/filetypes/link.svg "Paper")
