ash2 (absent, small, or homeotic)-like (Drosophila); Component of the Set1/Ash2 histone methyltransferase (HMT) complex, a complex that specifically methylates ’Lys-4’ of histone H3, but not if the neighboring ’Lys-9’ residue is already methylated. As part of the MLL1/MLL complex it is involved in methylation and dimethylation at ’Lys-4’ of histone H3. May function as a transcriptional regulator. May play a role in hematopoiesis (628 aa)

retinoblastoma binding protein 5; In embryonic stem (ES) cells, plays a crucial role in the differentiation potential, particularly along the neural lineage, regulating gene induction and H3 ’Lys-4’ methylation at key developmental loci, including that mediated by retinoic acid (By similarity). As part of the MLL1/MLL complex, involved in mono-, di- and trimethylation at ’Lys-4’ of histone H3. Histone H3 ’Lys-4’ methylation represents a specific tag for epigenetic transcriptional activation (538 aa)

WD repeat domain 82; Regulatory component of the SET1 complex implicated in the tethering of this complex to transcriptional start sites of active genes. Facilitates histone H3 ’Lys-4’ methylation via recruitment of the SETD1A or SETD1B to the ’Ser-5’ phosphorylated C-terminal domain (CTD) of RNA polymerase II large subunit (POLR2A). Component of PTW/PP1 phosphatase complex, which plays a role in the control of chromatin structure and cell cycle progression during the transition from mitosis into interphase (313 aa)

SET domain containing 1A; Histone methyltransferase that specifically methylates ’Lys-4’ of histone H3, when part of the SET1 histone methyltransferase (HMT) complex, but not if the neighboring ’Lys- 9’ residue is already methylated. H3 ’Lys-4’ methylation represents a specific tag for epigenetic transcriptional activation. The non-overalpping localization with SETD1B suggests that SETD1A and SETD1B make non-redundant contributions to the epigenetic control of chromatin structure and gene expression (1707 aa)

SET domain containing 1B; Histone methyltransferase that specifically methylates ’Lys-4’ of histone H3, when part of the SET1 histone methyltransferase (HMT) complex, but not if the neighboring ’Lys- 9’ residue is already methylated. H3 ’Lys-4’ methylation represents a specific tag for epigenetic transcriptional activation. The non-overalpping localization with SETD1A suggests that SETD1A and SETD1B make non-redundant contributions to the epigenetic control of chromatin structure and gene expression. Specifically tri-methylates ’Lys-4’ of histone H3 in vitro (1923 aa)

polymerase (RNA) II (DNA directed) polypeptide A, 220kDa; DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Largest and catalytic component of RNA polymerase II which synthesizes mRNA precursors and many functional non-coding RNAs. Forms the polymerase active center together with the second largest subunit. Pol II is the central component of the basal RNA polymerase II transcription machinery. It is composed of mobile elements that move relative to each other. RPB1 is part of the core element with the cen [...] (1970 aa)

WD repeat domain 38 (314 aa)

H2A histone family, member Y; Variant histone H2A which replaces conventional H2A in a subset of nucleosomes where it represses transcription. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post- translational modifications of histones, also called histone code, and nucleosome remodeling. Involved in stable X chromosome inactiv [...] (372 aa)