A Vertebrate Polycomb Response Element Governs Segmentation of the Posterior Hindbrain

Abstract

Chromatin remodeling by Polycomb group (PcG) and trithorax group (trxG) proteins regulates gene expression in all metazoans. Two major complexes, Polycomb repressive complexes 1 and 2 (PRC1 and PRC2), are thought to mediate PcG-dependent repression in flies and mammals. In Drosophila, PcG/trxG protein complexes are recruited by PcG/trxG response elements (PREs). However, it has been unclear how PcG/trxG are recruited in vertebrates. Here we have identified a vertebrate PRE, PRE-kr, that regulates expression of the mouse MafB/Kreisler gene. PRE-kr recruits PcG proteins in flies and mouse F9 cells and represses gene expression in a PcG/trxG-dependent manner. PRC1 and 2 bind to a minimal PRE-kr region, which can recruit stable PRC1 binding but only weak PRC2 binding when introduced ectopically, suggesting that PRC1 and 2 have different binding requirements. Thus, we provide evidence that similar to invertebrates, PREs act as entry sites for PcG/trxG chromatin remodeling in vertebrates.

MafB promotes atherosclerosis by inhibiting foam-cell apoptosis

“…42). In the rhombomere, the expression of MafB is regulated by a concentration gradient of retinoic acid 43,44 , indicating that the Mafb gene is a downstream target of the retinoic acid receptor, which dimerizes with RXR in the hindbrain. Furthermore, MafB is expressed in neural cells, podocytes in the kidney and the lens of the eye 26,45 .…”

Histone H2A Ubiquitination Inhibits the Enzymatic Activity of H3 Lysine 36 Methyltransferases

“…However, one important and not fully addressed question is the mechanism by which chromatin modifiers set up such modification patterns. Because of the critical role of Polycomb response elements in recruiting the Polycomb group proteins in Drosophila (63,64), and because there are only a few Polycomb response elements identified in mammals (65,66), alternative recruitment mechanisms, such as non-coding RNA-mediated PRC2 recruitment have been proposed and debated (67)(68)(69).…”

Multiple layers of complexity in cis‐regulatory regions of developmental genes

“…It has been shown that Polycomb-repressive complexes mediate chromatin compaction in flies and mice (Grau et al, 2011). This largescale chromatin change represses the expression of many developmental genes (Isono et al, 2005;Boyer et al, 2006;Lee et al, 2006;Lanzuolo et al, 2007;Sing et al, 2009). Another group of proteins, the GATA factors, regulate the conformation of chromatin, influencing gene expression (Vakoc et al, 2005).…”