title: Functional Conservation in the SIAMESE-RELATED Family of Cyclin-Dependent Kinase Inhibitors in Land Plants.
abstract: The best-characterized members of the plant-specific SIAMESE-RELATED (SMR) family of cyclin-dependent kinase inhibitors regulate the transition from the mitotic cell cycle to endoreplication, also known as endoreduplication, an altered version of the cell cycle in which DNA is replicated without cell division. Some other family members are implicated in cell cycle responses to biotic and abiotic stresses. However, the functions of most SMRs remain unknown, and the specific cyclin-dependent kinase complexes inhibited by SMRs are unclear. Here, we demonstrate that a diverse group of SMRs, including an SMR from the bryophyte Physcomitrella patens, can complement an Arabidopsis thaliana siamese (sim) mutant and that both Arabidopsis SIM and P. patens SMR can inhibit CDK activity in vitro. Furthermore, we show that Arabidopsis SIM can bind to and inhibit both CDKA;1 and CDKB1;1. Finally, we show that SMR2 acts to restrict cell proliferation during leaf growth in Arabidopsis and that SIM, SMR1/LGO, and SMR2 play overlapping roles in controlling the transition from cell division to endoreplication during leaf development. These results indicate that differences in SMR function in plant growth and development are primarily due to differences in transcriptional and posttranscriptional regulation, rather than to differences in fundamental biochemical function.
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Narender
authors.identifier: http://orcid.org/0000-0002-2009-3158
authors.initials: N
authors.lastname: Kumar
authors.affiliation: RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama, Kanagawa 230-0045, Japan.
authors.forename: Hirofumi
authors.identifier: http://orcid.org/0000-0003-3370-4111
authors.initials: H
authors.lastname: Harashima
authors.affiliation: Department of Biology, Molecular Plant Physiology, and Biotechnology, University of Antwerp, 2020 Antwerp, Belgium.
authors.forename: Shweta
authors.identifier: http://orcid.org/0000-0002-8293-6851
authors.initials: S
authors.lastname: Kalve
authors.affiliation: Institut de Biologie Moléculaire des Plantes du CNRS, IBMP-CNRS-UPR2357, Université de Strasbourg, F-67084 Strasbourg Cedex, France.
authors.forename: Jonathan
authors.identifier: http://orcid.org/0000-0002-9833-322X
authors.initials: J
authors.lastname: Bramsiepe
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Biology, Molecular Plant Physiology, and Biotechnology, University of Antwerp, 2020 Antwerp, Belgium.
authors.forename: Bulelani L
authors.identifier: http://orcid.org/0000-0002-2187-3770
authors.initials: BL
authors.lastname: Sizani
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Laura L
authors.initials: LL
authors.lastname: Bertrand
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Johnson
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Christopher
authors.identifier: http://orcid.org/0000-0002-9749-9658
authors.initials: C
authors.lastname: Faulk
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Renee
authors.initials: R
authors.lastname: Dale
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: L Alice
authors.initials: LA
authors.lastname: Simmons
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Michelle L
authors.identifier: http://orcid.org/0000-0002-6560-1056
authors.initials: ML
authors.lastname: Churchman
authors.affiliation: RIKEN Center for Sustainable Resource Science, Tsurumi, Yokohama, Kanagawa 230-0045, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Sugimoto
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Kato
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803.
authors.forename: Maheshi
authors.initials: M
authors.lastname: Dasanayake
authors.affiliation: Department of Biology, Molecular Plant Physiology, and Biotechnology, University of Antwerp, 2020 Antwerp, Belgium.
authors.forename: Gerrit
authors.identifier: http://orcid.org/0000-0001-6014-053X
authors.initials: G
authors.lastname: Beemster
authors.affiliation: Institut de Biologie Moléculaire des Plantes du CNRS, IBMP-CNRS-UPR2357, Université de Strasbourg, F-67084 Strasbourg Cedex, France.
authors.forename: Arp
authors.initials: A
authors.lastname: Schnittger
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803 jlarkin@lsu.edu.
authors.forename: John C
authors.identifier: http://orcid.org/0000-0002-7156-508X
authors.initials: JC
authors.lastname: Larkin
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000378:metabolism; D001696:Biomechanical Phenomena; D016923:Cell Death; D049109:Cell Proliferation; D017124:Conserved Sequence; D050756:Cyclin-Dependent Kinase Inhibitor Proteins / Q000378:metabolism*; D019669:Embryophyta / Q000235:genetics / Q000378:metabolism*; D062951:Endoreduplication; D055786:Gene Knockout Techniques; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D018515:Plant Leaves / Q000166:cytology / Q000254:growth & development / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011523:Protoplasts / Q000378:metabolism; D064201:Trichomes / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D010940:Plant Proteins