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ABAP1 is a novel plant Armadillo BTB protein involved in DNA replication and transcription
Author(s) -
Masuda Hana Paula,
Cabral Luiz Mors,
De Veylder Lieven,
Tanurdzic Milos,
de Almeida Engler Janice,
Geelen Danny,
Inzé Dirk,
Martienssen Robert A,
Ferreira Paulo CG,
Hemerly Adriana S
Publication year - 2008
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2008.191
Subject(s) - biology , transcription factor , microbiology and biotechnology , dna replication , mitosis , arabidopsis , transcription (linguistics) , cell division , genetics , origin recognition complex , gene , cell , eukaryotic dna replication , mutant , linguistics , philosophy
In multicellular organisms, organogenesis requires a tight control of the balance between cell division and cell differentiation. Distinct signalling pathways that connect both cellular processes with developmental cues might have evolved to suit different developmental plans. Here, we identified and characterized a novel protein that interacts with pre‐replication complex (pre‐RC) subunits, designated Armadillo BTB Arabidopsis protein 1 (ABAP1). Overexpression of ABAP1 in plants limited mitotic DNA replication and decreased cell proliferation in leaves, whereas ABAP1 downregulation increased cell division rates. Activity of ABAP1 in transcription was supported by its association with the transcription factor AtTCP24. The ABAP1–AtTCP24 complex bound specifically to the promoters of AtCDT1a and AtCDT1b in vitro and in vivo . Moreover, expression levels of AtCDT1a and AtCDT1b were reduced in ABAP1 ‐overexpressing plants and they were increased in plants with reduced levels of ABAP1. We propose that ABAP1 participates in a negative feedback loop regulating mitotic DNA replication during leaf development, either by repressing transcription of pre‐RC genes and possibly by regulating pre‐RC utilization through direct association with pre‐RC components.