title: Characterization and inhibition of AF10-mediated interaction.
abstract: The non-random chromosomal translocations t(10;11)(p13;q23) and t(10;11)(p13;q14-21) result in leukemogenic fusion proteins comprising the coiled coil domain of the transcription factor AF10 and the proteins MLL or CALM, respectively, and subsequently cause certain types of acute leukemia. The AF10 coiled-coil domain, which is crucial for the leukemogenic effect, has been shown to interact with GAS41, a protein previously identified as the product of an amplified gene in glioblastoma. Using sequential synthetic peptides, we mapped the potential AF10/GAS41 interaction site, which was subsequently be used as scaffold for a library targeting the AF10 coiled-coil domain. Using phage display, we selected a peptide that binds the AF10 coiled-coil domain with higher affinity than the respective coiled-coil region of wild-type GAS41, as demonstrated by phage ELISA, CD, and PCAs. Furthermore, we were able to successfully deploy the inhibitory peptide in a mammalian cell line to lower the expression of Hoxa genes that have been described to be overexpressed in these leukemias. This work dissects molecular determinants mediating AF10-directed interactions in leukemic fusions comprising the N-terminal parts of the proteins MLL or CALM and the C-terminal coiled-coil domain of AF10. Furthermore, it outlines the first steps in recognizing and blocking the leukemia-associated AF10 interaction in histiocytic lymphoma cells and therefore, may have significant implications in future diagnostics and therapeutics.
authors.affiliation: Molecular Biotechnology, University of Potsdam, Potsdam/Golm, Germany; Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Freiburg, Germany; Institute for Biology III, University of Freiburg, Freiburg, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Hagen
authors.forename: Dinah
authors.initials: D
authors.lastname: Mattay
authors.forename: Christina
authors.initials: C
authors.lastname: Räuber
authors.forename: Kristian M
authors.initials: KM
authors.lastname: Müller
authors.forename: Katja M
authors.initials: KM
authors.lastname: Arndt
mesh_terms: D057809:HEK293 Cells; D006801:Humans; D019151:Peptide Library; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000737:chemistry; D020298:U937 Cells
chemical_list: C092513:MLLT10 protein, human; D019151:Peptide Library; D010455:Peptides; D014157:Transcription Factors; C109446:YEATS4 protein, human
keywords: AF10; coiled coil; leucine zipper; protein design and selection; protein engineering; protein-protein interaction