RT Journal Article SR Electronic T1 MAF1, a Novel Plant Protein Interacting with Matrix Attachment Region Binding Protein MFP1, Is Located at the Nuclear Envelope JF The Plant Cell JO Plant Cell FD American Society of Plant Biologists SP 1755 OP 1767 DO 10.1105/tpc.11.9.1755 VO 11 IS 9 A1 Gindullis, Frank A1 Peffer, Nancy J. A1 Meier, Iris YR 1999 UL http://www.plantcell.org/content/11/9/1755.abstract AB The interaction of chromatin with the nuclear matrix via matrix attachment region (MAR) DNA is considered to be of fundamental importance for chromatin organization in all eukaryotic cells. MAR binding filament–like protein 1 (MFP1) from tomato is a novel plant protein that specifically binds to MAR DNA. Its filament protein–like structure makes it a likely candidate for a structural component of the nuclear matrix. MFP1 is located at nuclear matrix–associated, specklelike structures at the nuclear envelope. Here, we report the identification of a novel protein that specifically interacts with MFP1 in yeast two-hybrid and in vitro binding assays. MFP1 associated factor 1 (MAF1) is a small, soluble, serine/threonine-rich protein that is ubiquitously expressed and has no similarity to known proteins. MAF1, like MFP1, is located at the nuclear periphery and is a component of the nuclear matrix. These data suggest that MFP1 and MAF1 are in vivo interaction partners and that both proteins are components of a nuclear substructure, previously undescribed in plants, that connects the nuclear envelope and the internal nuclear matrix.