FACT in Cell Differentiation and Carcinogenesis

Recent work of several laboratories has identified FACT (facilitates chromatin transcription) protein complex as an emerging target for development of anticancer drugs and suggested a mechanism of FACT action during transcription and cell differentiation. FACT is the transcription and replication factor [1], which can stimulate transcript elongation through chromatin in vitro [2, 3]. Human FACT is a heterodimer composed of two subunits Spt16 and SSRP1 and has a histone chaperone activity [3, 4]. In vivo, FACT and RNA polymerase II (Pol II) co-localize and display similar kinetics of recruitment and chromosome tracking [5, 6]. FACT also maintains the nucleosome integrity during transcription initiation and transcript elongation by Pol II [6-9]. Currently, two different models have been proposed