This entry consists of AFF (AF4/FMR2) family of proteins which includes AFF1-AFF4 and the Drosophila protein Lilliputian [1-4]. Lilliputian acts in cytoskeleton regulation, segmentation and morphogenesis [2]. All AFF proteins are localised in the cel ...
This entry consists of AFF (AF4/FMR2) family of proteins which includes AFF1-AFF4 and the Drosophila protein Lilliputian [1-4]. Lilliputian acts in cytoskeleton regulation, segmentation and morphogenesis [2]. All AFF proteins are localised in the cell nucleus and are involved in regulation of gene expression. They are scaffold proteins that mediate the multisubunit super-elongation complex (SEC) assembly [1-4]. This entry represents the C-terminal homology domain (CHD, also known as C-terminal signature sequence), highly conserved among its members. This domain mediates the formation of an AFF4 homodimer or an AFF1-AFF4 heterodimer [4]. This domain is essential for AFF4 interaction with Transcription Start Site (TSS)-associated histone H3K27 whose acetylation signals SEC to regulate transcriptional elongation of the ESR1 gene [4]. Depletion of AFF4 reduces expression of ESR1, and, consequently inhibits breast cancer cell growth [4]. These proteins have been linked to human diseases such as acute lymphoblastic leukaemia and FRAXE [5].