Complex architecture of major histocompatibility complex class II promoters: reiterated motifs and conserved protein-protein interactions

N Jabrane-Ferrat, JD Fontes, JM Boss… - Molecular and cellular …, 1996 - Am Soc Microbiol
N Jabrane-Ferrat, JD Fontes, JM Boss, BM Peterlin
Molecular and cellular biology, 1996Am Soc Microbiol
The S box (also known as at the H, W, or Z box) is the 5′-most element of the conserved
upstream sequences in promoters of major histocompatibility complex class II genes. It is
important for their B-cell-specific and interferon gamma-inducible expression. In this study,
we demonstrate that the S box represents a duplication of the downstream X box. First, RFX,
which is composed of the RFX5-p36 heterodimer that binds to the X box, also binds to the S
box and its 5′-flanking sequence. Second, NF-Y, which binds to the Y box and increases …
Abstract
The S box (also known as at the H, W, or Z box) is the 5′-most element of the conserved upstream sequences in promoters of major histocompatibility complex class II genes. It is important for their B-cell-specific and interferon gamma-inducible expression. In this study, we demonstrate that the S box represents a duplication of the downstream X box. First, RFX, which is composed of the RFX5-p36 heterodimer that binds to the X box, also binds to the S box and its 5′-flanking sequence. Second, NF-Y, which binds to the Y box and increases interactions between RFX and the X box, also increases the binding of RFX to the S box. Third, RFXs bound to S and X boxes interact with each other in a spatially constrained manner. Finally, we confirmed these protein-protein and protein-DNA interactions by expressing a hybrid RFX5-VP16 protein in cells. We conclude that RFX binds to S and X boxes and that complex interactions between RFX and NF-Y direct B-cell-specific and interferon gamma-inducible expression of major histocompatibility complex class II genes.
American Society for Microbiology