KMT2A (myeloid/lymphoid or mixed lineage leukemia)

11q23.3

36 exons, multiple transcripts 13-15 kb.

3969 amino acids; 431 kDa; contains two DNA binding motifs (a AT hook and a CXXC domain), a DNA methyl transferase motif, a bromodomain. MLL is cleaved by taspase 1 into 2 proteins before entering the nucleus, called MLL-N and MLL-C. The FYRN and a FRYC domains of native MLL associate MLL-N and MLL-C in a stable complex; they form a multiprotein complex with transcription factor TFIID. MLL is a transcriptional regulatory factor. MLL can be associated with more than 30 proteins, including the core components of the SWI/SNF chromatin remodeling complex and the transcription complex TFIID. MLL binds promotors of HOX genes through acetylation and methylation of histones. MLL is a major regulator of hematopoesis and embryonic development.

ACER1 (alkaline ceramidase 1)

19p13.3

ACER1 is the alkaline ceramidase 1. Ceramidases catalyze hydrolysis of ceramide to generate sphingosine (SPH), which is phosphorylated to form sphingosine-1-phosphate (S1P). Ceramide, SPH, and S1P are bioactive lipids that mediate cell proliferation, differentiation, apoptosis, adhesion and migration (Mao and Obeid, 2008).