Isolation and functional characterisation of two new bZIP maize regulators of the ABA responsive gene rab28.
The plant hormone abscisic acid regulates gene expression in response to growth stimuli and abiotic stress. Previous studies have implicated members of the bZIP family of transcription factors as mediators of abscisic acid dependent gene expression through the ABRE cis-element. Here, we identify two new maize bZIP transcription factors, EmBP-2 and ZmBZ-1 related to EmBP-1 and OsBZ-8 families. They are differentially expressed during embryo development; EmBP-2 is constitutive, whereas ZmBZ-1 is abscisic acid-inducible and accumulates during late embryogenesis. Both factors are nuclear proteins that bind to ABREs and activate transcription of the abscisic acid-inducible gene rab28 from maize. EmBP-2 and ZmBZ-1 are phosphorylated by protein kinase CK2 and phosphorylation alters their DNA binding properties. Our data suggest that EmBP-2 and ZmBZ-1 are involved in the expression of abscisic acid inducible genes such as rab28 and their activity is modulated by ABA and by phosphorylation.
Nieva
Claudia
C
Departament de Genètica Molecular, IBMB, C.S.I.C., 08034, Barcelona, Spain.|Department of Zoology and Endocrinology, University of Ulm, 89081, Ulm, Germany.
Busk
Peter K
PK
Departament de Genètica Molecular, IBMB, C.S.I.C., 08034, Barcelona, Spain.|Department of Virology and Molecular Toxicology, Novo Nordisk Park, 2760, Måløv, Denmark.
Domínguez-Puigjaner
Eva
E
Departament de Genètica Molecular, IBMB, C.S.I.C., 08034, Barcelona, Spain.
Lumbreras
Victoria
V
Departament de Genètica Molecular, IBMB, C.S.I.C., 08034, Barcelona, Spain.
Testillano
Pilar S
PS
Plant Development and Nuclear Organization Unit, Biological Research Centre (CIB), C.S.I.C., C/Ramiro de Maeztu no. 9, 28040, Madrid, Spain.
Risueño
Maria-Carmen
MC
Plant Development and Nuclear Organization Unit, Biological Research Centre (CIB), C.S.I.C., C/Ramiro de Maeztu no. 9, 28040, Madrid, Spain.
Pagès
Montserrat
M
Departament de Genètica Molecular, IBMB, C.S.I.C., 08034, Barcelona, Spain. mptgmm@cid.csic.es.
D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D047390:Casein Kinase II / Q000378:metabolism; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D018515:Plant Leaves / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D020218:Response Elements / Q000235:genetics; D012639:Seeds / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015533:Transcriptional Activation / Q000235:genetics; D003313:Zea mays / Q000235:genetics*; D020691:rab GTP-Binding Proteins / Q000235:genetics*
D050976:Basic-Leucine Zipper Transcription Factors; D010940:Plant Proteins; C072238:Rab28 protein, Zea mays; D000040:Abscisic Acid; D047390:Casein Kinase II; D020691:rab GTP-Binding Proteins