MLL3 and MLL4 Methyltransferases Bind to the MAFA and MAFB Transcription Factors to Regulate Islet β-Cell Function.

ABSTRACT: Insulin produced by islet β-cells plays a critical role in glucose homeostasis, with type 1 and type 2 diabetes both resulting from inactivation and/or loss of this cell population. Islet-enriched transcription factors regulate β-cell formation and function, yet little is known about the molecules recruited to mediate control. An unbiased in-cell biochemical and mass spectrometry strategy was used to isolate MafA transcription factor-binding proteins. Among the many coregulators identified were all of the subunits of the mixed-lineage leukemia 3 (Mll3) and 4 (Mll4) complexes, with histone 3 lysine 4 methyltransferases strongly associated with gene activation. MafA was bound to the ∼1.5 MDa Mll3 and Mll4 complexes in size-fractionated β-cell extracts. Likewise, closely related human MAFB, w

SUBMITTER: Scoville DW 

PROVIDER: S-EPMC4613979 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature