title: EFFECTOR OF TRANSCRIPTION2 is involved in xylem differentiation and includes a functional DNA single strand cutting domain.
abstract: EFFECTORS OF TRANSCRIPTION2 (ET) are plant-specific regulatory proteins characterized by the presence of two to five C-terminal DNA- and Zn-binding repeats, and a highly conserved cysteine pattern. We describe the structural characterization of the three member Arabidopsis thaliana ET gene family and reveal some allelic sequence polymorphisms. A mutation analysis showed that AtET2 affects the expression of various KNAT genes involved in the maintenance of the undifferentiated state of cambial meristem cells. It also plays a role in the regulation of GA5 (gibberellin 3-beta-dioxygenase) and the cell-cycle-related GASA4. A correlation was established between AtET2 expression and the cellular differentiation state. AtET-GFP fusion proteins shuttle between the cytoplasm and nucleus, with the AtET2 product prevented from entering the nucleus in non-differentiating cells. Within the nucleus, AtET2 probably acts via a single strand cutting domain. A more general regulatory role for ET factors is proposed, governing cell differentiation in cambial meristems, a crucial process for the development of plant vascular tissues.
authors.affiliation: Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, D-06466 Gatersleben, Germany.
authors.forename: Rumen
authors.initials: R
authors.lastname: Ivanov
authors.forename: Jens
authors.initials: J
authors.lastname: Tiedemann
authors.forename: Andreas
authors.initials: A
authors.lastname: Czihal
authors.forename: Anna
authors.initials: A
authors.lastname: Schallau
authors.forename: Le Hong
authors.initials: le H
authors.lastname: Diep
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Mock
authors.forename: Bernhard
authors.initials: B
authors.lastname: Claus
authors.forename: Annegret
authors.initials: A
authors.lastname: Tewes
authors.forename: Helmut
authors.initials: H
authors.lastname: Bäumlein
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D018506:Gene Expression Regulation, Plant; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D052584:Xylem / Q000166:cytology*
chemical_list: D029681:Arabidopsis Proteins; C526037:ET1 protein, Arabidopsis; C526038:ET2 protein, Arabidopsis; C526039:ET3 protein, Arabidopsis; D014157:Transcription Factors