Long non-coding RNAs (lncRNAs) are emerging as important regulators of cellular processes
and are extensively involved in the development of different cancers; including leukemias.
As one of the accepted methods of lncRNA function is affecting chromatin structure;
lncRNA binding has been shown for different chromatin modifiers. Histone lysine methyltransferases
(HKMTs) are also subject of lncRNA regulation as demonstrated for example in the case
of Polycomb Repressive Complex 2 (PRC2). Mixed Lineage Leukemia (MLL) proteins that
catalyze the methylation of H3K4 have been implicated in several different cancers;
yet many details of their regulation and targeting remain elusive. In this work we
explored the RNA binding capability of two; so far uncharacterized regions of MLL4;
with the aim of shedding light to the existence of possible regulatory lncRNA interactions
of the protein. We demonstrated that both regions; one that contains a predicted RNA
binding sequence and one that does not; are capable of binding to different RNA constructs
in vitro. To our knowledge, these findings are the first to indicate that an MLL protein
itself is capable of lncRNA binding.
