MIDA1 is a sequence specific DNA binding protein with novel DNA binding properties

Abstract

Background: Id proteins not only regulate cell differentiation negatively, but they also promote growth and apoptosis. To know the mechanism of how Id regulates cell fate, we previously isolated an Idassociating protein, MIDA1, which positively regulates cell growth. Its predicted amino acid sequence contains tryptophan-mediated repeats (Tryp-med repeats) similar to the DNA binding region of the cMyb oncoprotein. We determined whether MIDA1 can bind to DNA in a sequence speci®c manner by PCR-assisted binding site selection.

The chaperones MPP11 and Hsp70L1 form the mammalian ribosome-associated complex

“…First, the entire zuotin-homology region binds to the left-handed DNA conformation, termed Z-DNA in vitro (18). Second, the Myb domain of MIDA1 recognizes a specific hairpin structure consisting of seven nucleotides surrounded by a short palindrome (20). Third, DNA binding in vivo was suggested based on the ability of MIDA1 to act as a transcriptional activator (21).…”

“…Id1 is a member of a family of helix-loop-helix proteins involved in cell type-specific transcription and cell lineage commitment (19). In addition, it was found that MIDA1 displays DNAbinding activity (18,20). According to the current model, MPP11͞ MIDA1 is a multifunctional protein involved in transcriptional control through interaction with multiple factors (21).…”

Id and development

“…These include MIDA1 (Shoji et al, 1995;Inoue et al, 1999Inoue et al, , 2000, Pax2, Pax5 and Pax8 (Roberts et al, 2001), Elk-1 (Yates et al, 1999), c-Ets-1 (Ohtani et al, 2001) and the retinoblastoma protein family (Iavarone et al, 1994;Lasorella et al, 1996Lasorella et al, , 2000. Elucidation of the detailed relationships of Id proteins with these factors would reveal novel roles for Id proteins in di erentiation and proliferation controls, and promote our understanding of how di erentiation and proliferation are regulated.…”

Id proteins in cell cycle control and cellular senescence

“…In addition to the pRB-and Ets-family proteins, three additional non-bHLH proteins, MIDA1 (Shoji et al, 1995;Inoue et al, 2000), Pax transcription factors (Roberts et al, 2001) and adenovirus E1A protein (Nakajima et al, 1998) also interact with Id proteins. Therefore, Id is likely to have di erent functions depending on the binding target.…”