The Negative Elongation Factor Complex – a poorly understood multi-faceted transcript-processing complex

Abstract

With the advent of whole genome screens, promoter-proximal pausing of RNA polymerase II (RNAPII) has been shown to play a much more significant role in eukaryotic systems than previously thought. This type of transcription inhibition is dependent on the binding of the Negative Elongation Factor(NELF) complex which is composed of four sub-units, presenting unique domains and consequently fulfilling different functions. Numerous questions still surround the mechanism by which NELF is recruited, stabilised and dissociated from the RNAPII complex. Furthermore, not much is known about which other transcription stages the NELF complex is involved in and through which sub-units it carries out such functions. Based on the current knowledge of the role of NELF in transcription pausing, it is hypothesised that different interaction partners are required to direct context-specific functions of the NELF complex. This review covers some of the known roles and contexts in which NELF acts in an attempt to identify key questions for future NELF-dependent transcriptional research.