title: The maize transfer cell-specific type-A response regulator ZmTCRR-1 appears to be involved in intercellular signalling.
abstract: Response regulators are signal-transduction molecules present in bacteria, yeast and plants, acting as relays for environmental challenges. This paper reports the characterization of a Zea mays gene, ZmTCRR-1, that codes for a member of the type-A response regulator class of proteins. The gene was found to be expressed exclusively in the endosperm transfer-cell layer 8-14 days after pollination, when transfer-cell differentiation is most active. The promoter of ZmTCRR-1 was strongly transactivated in heterologous systems by the transfer cell-specific transcription factor ZmMRP-1. The ZmTCRR-1 protein was detected not only in the transfer-cell layer, but also in the conductive tissue deep inside the endosperm, where there is no transcription of the gene. This suggests that two-component systems might be involved in intercellular signal transmission, in contrast to the generally held belief that these systems are involved only in cell-autonomous pathways.
authors.affiliation: Departamento de Biología Celular y Genética, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Muñiz
authors.forename: Joaquín
authors.initials: J
authors.lastname: Royo
authors.forename: Elisa
authors.initials: E
authors.lastname: Gómez
authors.forename: Cristina
authors.initials: C
authors.lastname: Barrero
authors.forename: Diego
authors.initials: D
authors.lastname: Bergareche
authors.forename: Gregorio
authors.initials: G
authors.lastname: Hueros
mesh_terms: D000595:Amino Acid Sequence; D002454:Cell Differentiation / Q000235:genetics; D018628:Gene Dosage; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011401:Promoter Regions, Genetic; D012639:Seeds / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction / Q000235:genetics*; D003313:Zea mays / Q000196:embryology / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins