ASXL2 (additional sex combs like 2, transcriptional regulator)

2p23.3

Polycomb-group (PcG) and trithorax-group (trxG) proteins regulate histone methylation to establish repressive and active chromatin configurations in Drosophila. Mutations in Asx (the homolog of ASXL2) enhance both Polycomb-group (PcG) and trithorax-group (trxG) mutant phenotypes (Baskind et al., 2009). ASXL2 is an enhancer of PcG activity. ASXL2 and the histone methyltansferase EZH2 (7q36) directly represses MYH7 (14q11) (Beta-Myosin Heavy Chain) (Lai et al., 2012). ASXL2 is implicated in prostate, breast, pancreatic cancers (review in Katoh, 2013). EPC1-ASXL2 fusion gene has been found in adult T-cell leukaemia/lymphoma with a t(2;10)(p23;p11) (Nakahata et al., 2009). EPC1 (10p11) is also a component of the histone acetyltransferase complex.

KAT6A (MYST histone acetyltransferase (monocytic leukemia) 3

8p11.21

KAT6A is also known as MYST3, or MOZ.

KAT6A is a histone acetyltransferase (HAT). KAT6A has intrinsic HAT activity; KAT6A also forms complexes with MEAF6 (1p34), ING5 (2q37), and BRPF1 (3p25) to acetylate histones H3. KAT6A is a transcriptional co-activator; it interacts with RUNX1 (21q22) and SPI1/PU.1 (11p11) to regulate the expression of haematopoietic-related genes; KAT6A and MLL (11q23), an histone methyltransferase, cooperate to regulate HOX genes, which are key genes in human cord blood CD34+ cells progenitors, and are critical for leukemogenesis. KAT6A is also an epigenetic regulator of haematopoiesis (reviews in Perez-Campo et al., 2013; Yang and Ullah, 2007).