Transcriptional activation of the maize endosperm transfer cell-specific gene BETL1 by ZmMRP-1 is enhanced by two C2H2 zinc finger-containing proteins.
ZmMRP-1 is a single MYB-domain transcription factor specifically expressed in the transfer cell layer of the maize endosperm, where it directly regulates the expression of a number of transfer cell specific genes and very likely contributes to the regulation of the transfer cell differentiation process. It is still a matter of debate, however, how this type of transcription factors interact with the promoter sequences they regulate. In this work we have investigated the existence of proteins interacting with ZmMRP-1 in the transfer cell nuclei. In a yeast double-hybrid screen we identified two related maize proteins, ZmMRPI-1 and ZmMRPI-2 belonging to the C(2)H(2) zinc finger protein family, which interact with ZmMRP-1 and modulate its activity on transfer cell specific promoters. Two ZmMRPI orthologous genes were also identified in the rice and Arabidopsis genomes. The expression pattern in maize and Arabidopsis suggest a role for these proteins in gene regulation at the exchange surfaces where ZmMRP-1 is expressed providing the first indication of their function. We show that this previously uncharacterized family of proteins encodes nuclear proteins that interact with MYB-related transcription factors through their C-terminal conserved domain.
Royo
Joaquín
J
Dpto. Biología Celular y Genética, Universidad de Alcalá, Campus Universitario, Alcalá de Henares 28870, Madrid, Spain.
Gómez
Elisa
E
Barrero
Cristina
C
Muñiz
Luis Miguel
LM
Sanz
Yolanda
Y
Hueros
Gregorio
G
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D017343:Genes, Plant; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D009928:Organ Specificity; D010641:Phenotype; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D012639:Seeds / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics*; D020798:Two-Hybrid System Techniques; D003313:Zea mays / Q000235:genetics*; D016335:Zinc Fingers / Q000235:genetics*
D009687:Nuclear Proteins; D010940:Plant Proteins