RESUMEN
Hyper-activated STAT5B variants are high value oncology targets for pharmacologic intervention. STAT5BN642H, a frequently-occurring oncogenic driver mutation, promotes aggressive T-cell leukemia/lymphoma in patient carriers, although the molecular origins remain unclear. Herein, we emphasize the aggressive nature of STAT5BN642H in driving T-cell neoplasia upon hematopoietic expression in transgenic mice, revealing evidence of multiple T-cell subset organ infiltration. Notably, we demonstrate STAT5BN642H-driven transformation of γδ T-cells in in vivo syngeneic transplant models, comparable to STAT5BN642H patient γδ T-cell entities. Importantly, we present human STAT5B and STAT5BN642H crystal structures, which propose alternative mutation-mediated SH2 domain conformations. Our biophysical data suggests STAT5BN642H can adopt a hyper-activated and hyper-inactivated state with resistance to dephosphorylation. MD simulations support sustained interchain cross-domain interactions in STAT5BN642H, conferring kinetic stability to the mutant anti-parallel dimer. This study provides a molecular explanation for the STAT5BN642H activating potential, and insights into pre-clinical models for targeted intervention of hyper-activated STAT5B.
Asunto(s)
Linfocitos Intraepiteliales , Leucemia de Células T/genética , Linfoma de Células T/genética , Mutación , Factor de Transcripción STAT5/genética , Animales , Neoplasias Hematológicas/genética , Humanos , Ratones , Ratones Transgénicos , Simulación del Acoplamiento Molecular , Dominios Homologos srcRESUMEN
Bacteriophage Mu C protein is an activator of the four Mu late promoters that drive the expression of genes encoding DNA-modification as well as phage head and tail morphogenesis proteins. This report describes the purification and cocrystallization of wild-type and selenomethionine-substituted C protein with a synthetic late promoter P(sym), together with preliminary X-ray diffraction data analysis using SAD phasing. The selenomethionine peak data set was collected from a single crystal which diffracted to 3.1 A resolution and belonged to space group P4(1) or P4(3), with unit-cell parameters a = 68.9, c = 187.6 A and two complexes per asymmetric unit. The structure will reveal the amino acid-DNA interactions and any conformational changes associated with DNA binding.
