AHM1, a Novel Type of Nuclear Matrix-Localized, MAR Binding Protein with a Single AT Hook and a J Domain-Homologous Region

• Published in: The Plant cell 2000-10, Vol.12 (10), p.1903-1916
• Main Authors: Morisawa, Gaku, Han-yama, Atsushi, Moda, Ichiro, Tamai, Atsushi, Iwabuchi, Masaki, Meshi, Tetsuo
• Format: Article
• Language: English
• Subjects: AHM1 protein; Amino Acid Sequence; Amino acids; AT hook-containing MAR-binding protein 1; Binding Sites; Carrier proteins; Cloning, Molecular; Complementary DNA; DNA; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Escherichia coli; Genomics; HeLa cells; Matrix Attachment Region Binding Proteins; matrix attachment regions; Molecular Sequence Data; Nuclear matrix; Nuclear Matrix - metabolism; Nuclear Proteins - chemistry; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Plant cells; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Polydeoxyribonucleotides - metabolism; Proteins; Recombinant Proteins - chemistry; Recombinant Proteins - metabolism; Sequence Alignment; Sequence Homology, Amino Acid; Triticum - genetics; Triticum - metabolism; Triticum aestivum; Yeasts; Zinc Fingers
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.12.10.1903

Interactions between the nuclear matrix and special regions of chromosomal DNA called matrix attachment regions (MARs) have been implicated in various nuclear functions. We have identified a novel protein from wheat, AT hook-containing MAR binding protein1 (AHM1), that binds preferentially to MARs. A multidomain protein, AHM1 has the special combination of a J domain-homologous region and a Zn finger-like motif (a J-Z array) and an AT hook. For MAR binding, the AT hook at the C terminus was essential, and an internal portion containing the Zn finger-like motif was additionally required in vivo. AHM1 was found in the nuclear matrix fraction and was localized in the nucleoplasm. AHM1 fused to green fluorescent protein had a speckled distribution pattern inside the nucleus. AHM1 is most likely a nuclear matrix component that functions between intranuclear framework and MARs. J-Z arrays can be found in a group of (hypothetical) proteins in plants, which may share some functions, presumably to recruit specific Hsp70 partners as co-chaperones.