Negative elongation factor
Encyclopedia
NELF is a four subunit protein (NELF-A, NELF-B, NELF-C or NELF-D, NELF-E) that affects transcription by RNA polymerase II
. Subunit NELF-E is also known as RDBP
. The NELF-A subunit is encoded by the gene WHSC2
, Wolf-Hirschhorn syndrome candidate 2. NELF-C and NELF-D are probably peptides resulting from the same mRNA with different translation initiation site, possibly differing only in an extra 9 amino acids for NELF-C at the N-terminus. Or, it is possible they arise from different mRNAs. A single NELF complex consists of either NELF-C or NELF-D but not both. Microsequencing analysis showed that NELF-B was the protein previously identified as the protein encoded by the gene COBRA1, and shown to interact with BRCA1
.
NELF binds in a stable complex with DSIF
and RNA Polymerase II together, but not with either alone. P-TEFb
inhibits the effect of NELF and DSIF on Pol II elongation, via its phosphorylation of Serine 2 on the C-terminal domain of Pol II, and the SPT5 subunit of DSIF, causing dissociation of NELF. NELF homologues exist in some metazoans (e.g. insects and vertebrates) but have not been found in plants, yeast, or nematode (worms).
RNA polymerase II
RNA polymerase II is an enzyme found in eukaryotic cells. It catalyzes the transcription of DNA to synthesize precursors of mRNA and most snRNA and microRNA. A 550 kDa complex of 12 subunits, RNAP II is the most studied type of RNA polymerase...
. Subunit NELF-E is also known as RDBP
RDBP
Negative elongation factor E is a protein that in humans is encoded by the RDBP gene.-Interactions:RDBP has been shown to interact with TH1L, WHSC2 and Cofactor of BRCA1.-External links:...
. The NELF-A subunit is encoded by the gene WHSC2
WHSC2
Negative elongation factor A is a protein that in humans is encoded by the WHSC2 gene.-Further reading:...
, Wolf-Hirschhorn syndrome candidate 2. NELF-C and NELF-D are probably peptides resulting from the same mRNA with different translation initiation site, possibly differing only in an extra 9 amino acids for NELF-C at the N-terminus. Or, it is possible they arise from different mRNAs. A single NELF complex consists of either NELF-C or NELF-D but not both. Microsequencing analysis showed that NELF-B was the protein previously identified as the protein encoded by the gene COBRA1, and shown to interact with BRCA1
BRCA1
BRCA1 is a human caretaker gene that produces a protein called breast cancer type 1 susceptibility protein, responsible for repairing DNA. The first evidence for the existence of the gene was provided by the King laboratory at UC Berkeley in 1990...
.
NELF binds in a stable complex with DSIF
DSIF
DSIF is a factor that can either negatively or positively affect transcription by RNA polymerase II . In one case of negative regulation, it can interact with NELF to promote the stalling of Pol II at some genes. This stalling is released by P-TEFb. In humans, DSIF is composed of hSPT4 and...
and RNA Polymerase II together, but not with either alone. P-TEFb
P-TEFb
Positive Transcription Elongation Factor b is the key factor regulating eukaryotic mRNA transcription at the level of elongation.It is a cyclin dependent kinase, composed of Cdk9 and in humans one of three cyclins, T1, T2, or K....
inhibits the effect of NELF and DSIF on Pol II elongation, via its phosphorylation of Serine 2 on the C-terminal domain of Pol II, and the SPT5 subunit of DSIF, causing dissociation of NELF. NELF homologues exist in some metazoans (e.g. insects and vertebrates) but have not been found in plants, yeast, or nematode (worms).