Inducible STAT3 NH2 terminal mono-ubiquitination promotes BRD4 complex formation to regulate apoptosis.

ABSTRACT: Signal Transducers and Activator of Transcription-3 (STAT3) are latent transcription factors that are regulated by post-translational modifications (PTMs) in response to cellular activation by the IL-6 superfamily of cytokines to regulate cell cycle progression and/or apoptosis. Here we observe that STAT3 is inducibly mono-ubiquitinated and investigate its consequences. Using domain mapping and highly specific selected reaction monitoring-mass spectrometric assays, we identify lysine (K) 97 in its NH2-terminal domain as the major mono-ubiquitin conjugation site. We constructed a mono-ubiquitinated mimic consisting of a deubiquitinase-resistant monomeric ubiquitin fused to the NH2 terminus of STAT3 (ubiquitinated-STAT3 FP). In complex assays of ectopically expressed ubi-STAT3-FP, we observe

SUBMITTER: Ray S 

PROVIDER: S-EPMC4067092 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature