title: A family of cyclin D homologs from plants differentially controlled by growth regulators and containing the conserved retinoblastoma protein interaction motif.
abstract: A new family of three related cyclins has been identified in Arabidopsis by complementation of a yeast strain deficient in G1 cyclins. Individual members show tissue-specific expression and are conserved in other plant species. They form a distinctive group of plant cyclins, which we named delta-type cyclins to indicate their similarities with mammalian D-type cyclins. The sequence relationships between delta and D cyclins include the N-terminal sequence LXCXE. This motif was originally identified in certain viral oncoproteins and is strongly implicated in binding to the retinoblastoma protein pRb. By analogy to mammalian cyclin D, these plant homologs may mediate growth and phytohormonal signals into the plant cell cycle. In support of this hypothesis, we show that, on restimulation of suspension-cultured cells, cyclin delta 3 is rapidly induced by the plant growth regulator cytokinin and cyclin delta 2 is induced by carbon source.
authors.affiliation: Institute of Biotechnology, University of Cambridge, United Kingdom.
authors.forename: R
authors.initials: R
authors.lastname: Soni
authors.forename: J P
authors.initials: JP
authors.lastname: Carmichael
authors.forename: Z H
authors.initials: ZH
authors.lastname: Shah
authors.forename: J A
authors.initials: JA
authors.lastname: Murray
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis; D001483:Base Sequence; D002244:Carbon / Q000378:metabolism; D017124:Conserved Sequence; D016213:Cyclins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D006801:Humans; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000502:physiology; D016160:Retinoblastoma Protein / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D013045:Species Specificity
chemical_list: D016213:Cyclins; D010937:Plant Growth Regulators; D016160:Retinoblastoma Protein; D002244:Carbon