EFFECTOR OF TRANSCRIPTION2 is involved in xylem differentiation and includes a functional DNA single strand cutting domain.
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.
Ivanov
Rumen
R
Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, D-06466 Gatersleben, Germany.
Tiedemann
Jens
J
Czihal
Andreas
A
Schallau
Anna
A
Diep
Le Hong
le H
Mock
Hans-Peter
HP
Claus
Bernhard
B
Tewes
Annegret
A
Bäumlein
Helmut
H
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*
D029681:Arabidopsis Proteins; C526037:ET1 protein, Arabidopsis; C526038:ET2 protein, Arabidopsis; C526039:ET3 protein, Arabidopsis; D014157:Transcription Factors