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Arabidopsis chromatin-associated HMGA and HMGB use different nuclear targeting signals and display highly dynamic localization within the nucleus.
- Source :
-
The Plant cell [Plant Cell] 2006 Nov; Vol. 18 (11), pp. 2904-18. Date of Electronic Publication: 2006 Nov 17. - Publication Year :
- 2006
-
Abstract
- In plants, the chromatin-associated high mobility group (HMG) proteins occur in two subfamilies termed HMGA and HMGB. The HMGA proteins are characterized by the presence of four AT-hook DNA binding motifs, and the HMGB proteins contain an HMG box DNA binding domain. As architectural factors, the HMG proteins appear to be involved in the regulation of transcription and other DNA-dependent processes. We have examined the subcellular localization of Arabidopsis thaliana HMGA, HMGB1, and HMGB5, revealing that they localize to the cell nucleus. They display a speckled distribution pattern throughout the chromatin of interphase nuclei, whereas none of the proteins associate with condensed mitotic chromosomes. HMGA is targeted to the nucleus by a monopartite nuclear localization signal, while efficient nuclear accumulation of HMGB1/5 requires large portions of the basic N-terminal part of the proteins. The acidic C-terminal domain interferes with nucleolar targeting of HMGB1. Fluorescence recovery after photobleaching experiments revealed that HMGA and HMGB proteins are extremely dynamic in the nucleus, indicating that they bind chromatin only transiently before moving on to the next site, thereby continuously scanning the genome for targets. By contrast, the majority of histone H2B is basically immobile within the nucleus, while linker histone H1.2 is relatively mobile.
- Subjects :
- AT-Hook Motifs genetics
Amino Acid Sequence
Amino Acids, Basic metabolism
Arabidopsis cytology
Arabidopsis Proteins chemistry
Chromosomes, Plant metabolism
DNA, Plant metabolism
Fluorescence Recovery After Photobleaching
Green Fluorescent Proteins metabolism
HMGA Proteins chemistry
HMGB Proteins chemistry
HMGB1 Protein chemistry
Histones metabolism
Interphase
Mitosis
Molecular Sequence Data
Nuclear Localization Signals metabolism
Protein Transport
Protoplasts cytology
Recombinant Fusion Proteins metabolism
Seedlings cytology
Nicotiana cytology
Arabidopsis metabolism
Arabidopsis Proteins metabolism
Cell Nucleus metabolism
Chromatin metabolism
HMGA Proteins metabolism
HMGB Proteins metabolism
HMGB1 Protein metabolism
Signal Transduction
Subjects
Details
- Language :
- English
- ISSN :
- 1040-4651
- Volume :
- 18
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- The Plant cell
- Publication Type :
- Academic Journal
- Accession number :
- 17114349
- Full Text :
- https://doi.org/10.1105/tpc.106.047274