title: TM20, a gene coding for a new class of transmembrane proteins expressed in the meristematic tissues of maize.
abstract: In the course of the analysis of lachrima, a recessive, defective kernel, embryo-lethal mutation in Zea mays that alters embryo and endosperm development, a gene coding for a new class of transmembrane proteins was isolated. The mutant was produced by Ac transposon tagging, and a gene located in the insertion region of the transposon was isolated as well as the corresponding cDNA. The predicted protein contains twenty hydrophobic segments that can be grouped in five repeats formed by four segments that fulfill the criteria for membrane spanning domains, and for this reason the gene has been named TM20. The sequences of the domains in each position of each group can be aligned, indicating that TM20 is formed by a four-domain structure duplicated five times. During embryogenesis in wild-type embryos and in the growing plant, TM20 gene expression is associated with meristems.
authors.affiliation: Departament de Genètica Molecular, Institut de Biologia Molecular de Barcelona, Centre d'Investigació i Desenvolupament, Consejo Superior de Investigaciones Científicas, Jordi Girona, 18, 08034 Barcelona, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Stiefel
authors.forename: E L
authors.initials: EL
authors.lastname: Becerra
authors.forename: R
authors.initials: R
authors.lastname: Roca
authors.forename: M
authors.initials: M
authors.lastname: Bastida
authors.forename: T
authors.initials: T
authors.lastname: Jahrmann
authors.forename: E
authors.initials: E
authors.lastname: Graziano
authors.forename: P
authors.initials: P
authors.lastname: Puigdomènech
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008565:Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D018519:Meristem / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics; D017433:Protein Structure, Secondary; D012639:Seeds / Q000502:physiology; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*
chemical_list: D004251:DNA Transposable Elements; D008565:Membrane Proteins; D010940:Plant Proteins; C121941:TM20 protein, Zea mays