A model of MTG16-mediated repression in the SCL/TAL1:E2A complex. (a) A number of studies concur that MTG16 represses genes poised for rapid activation upon terminal differentiation. MTG16 interacts with the SCL/TAL1:E2A complex in erythroid progenitors and prevents the expression of several erythrocytic genes, including α-globin
, and CDKN1A.
The cartoon figure describes the complex dynamics involved in erythroid maturation as described by Schuh et al. [55
]. In the erythroid progenitor stage, the complex interacts with MTG16 and Gfi1, but upon differentiation, both MTG16 and Gfi1 dissociate from the complex, allowing for the recruitment of coactivator complexes (p300/CBP) to promote gene transcription. (b). Although not as extensively researched, MTG16 likely plays a similar repressive role in actively dividing HSPCs. The SCL/TAL1 complex activates expression of genes that help to preserve quiescence. Expression of MTG16 can repress these genes and induce a proliferative state in HSPCs. The details of these complex dynamics have not been fully elucidated in HSCs/HSPCs.