Long-term l-3,4-dihydroxyphenylalanine (L-Dopa) treatment in Parkinson's disease leads to involuntary movements called dyskinesia, notably through an overexpression of immediate-early genes (IEG). Their rapid transcription involves the stalling of RNA polymerase II on IEG promoters, a mechanism tha
t critically depends on the presence of the negative elongation factor (NELF) protein complex. We here down-regulated the key NELF-E subunit using lentiviral vector delivery of a short hairpin RNA in the striatum of 6-hydroxydopamine lesioned rats. Such NELF-E reduced expression significantly attenuated the development of abnormal involuntary movements in response to chronic L-Dopa treatment. Effectiveness of silencing was demonstrated by the significant decrease in striatal FosB, ARC and Zif268 IEG expression. Repression of NELF-mediating RNA polymerase II stalling thus achieves both antidyskinetic and potentiation of antiparkinsonian L-Dopa effect, highlighting the role of transcriptional events in dyskinesia establishment, acute dyskinetic manifestation and in the therapeutic response to L-Dopa.
As the mouse nasal embryonic LHRH factor gene (Nelf) encodes a guidance molecule for the migration of the olfactory axon and gonadotropin-releasing hormone neurons, its human homolog, NELF, is a candidate gene for Kallmann s
yndrome, a disease of idiopathic hypogonadotropic hypogonadism (IHH) with anosmia or hyposmia. We report here characterization of NELF and results of mutation analysis in 65 IHH patients. Assembling EST clones, RACE, and sequencing showed that NELF mapped to 9q34.3 is composed of 16 exons and 15 introns with a 1,590-bp ORF encoding 530 amino acids. RT-PCR on a fetal brain cDNA library revealed five alternatively spliced variants. Among them, NELF-v1 has 93-94% identity at the amino acid level to mouse/rat Nelf, and four other transcripts are also highly conserved among the three species. A 3.0-kb transcript is expressed most highly in the adult and fetal brain, testis, and kidney, indicating that NELF plays a role in the function of these tissues. Mutation screening detected in a patient with IHH one novel heterozygous missense mutation (1438A>G, T480A) at the donor-splice site in exon 15 of NELF. As this mutation was not found in 100 normal control individuals, T480A may be associated with IHH. Four other novel SNPs (102C > T and 1029C > T within the coding region, and two IVS14+47C > T and IVS15+41G > A) were also identified in NELF.
Fujita T, etal., Exp Cell Res. 2009 Jan 15;315(2):274-84. doi: 10.1016/j.yexcr.2008.10.032. Epub 2008 Nov 5.
The transcription rate of immediate early genes (IEGs) is controlled directly by transcription elongation factors at the transcription elongation step. Negative elongation factor (NELF) and 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) sensitivity-indu
cing factor (DSIF) stall RNA polymerase II (pol II) soon after transcription initiation. Upon induction of IEG transcription, DSIF is converted into an accelerator for pol II elongation. To address whether and how NELF as well as DSIF controls overall IEG transcription, its expression was reduced using stable RNA interference in GH4C1 cells. NELF knock-down reduced thyrotropin-releasing hormone (TRH)-induced transcription of the IEGs c-fos, MKP-1, and junB. In contrast, epidermal growth factor (EGF)-induced transcription of these IEGs was unaltered or even slightly increased by NELF knock-down. Thus, stable knock-down of NELF affects IEG transcription stimulation-specifically. Conversely, DSIF knock-down reduced both TRH- and EGF-induced transcription of the three IEGs. Interestingly, TRH-induced activation of the MAP kinase pathway, a pathway essential for transcription of the three IEGs, was down-regulated by NELF knock-down. Thus, stable knock-down of NELF, by modulating intracellular signaling pathways, caused stimulation-specific loss of IEG transcription. These observations indicate that NELF controls overall IEG transcription via multiple mechanisms both directly and indirectly.
Dai W, etal., Front Biosci (Landmark Ed). 2025 Apr 25;30(4):25221. doi: 10.31083/FBL25221.
BACKGROUND: To investigate the significance of the negative elongation factor complex member C/D (NELFCD) in colon cancer progression. METHODS: Immunohistochemistry staining, Western blot analysis, and real-time quantitative polymerase chain
reaction (RT-qPCR) were used to quantify the protein/gene levels. NELFCD-protein arginine methyltransferase 5 (PRMT5) interaction was determined by co-immunoprecipitation assay. A chromatin immunoprecipitation (ChIP) assay was performed to determine the interaction between the promoter region of dual specificity phosphatase 2 (DUSP2), NELFCD, and PRMT5. Cell growth and cell cycle progression were assessed using the cell counting kit-8 proliferation assay, colony formation assay, and/or flow cytometry. RESULTS: NELFCD was upregulated in colon cancer and promoted cancer cell growth. In colon cancer cells, the expression of NELFCD was negatively correlated with DUSP2 expression. The RNA sequencing results indicated that genes in the mitogen-activated protein kinase (MAPK) signaling pathway as well as DUSP2 were affected by NELFCD. The ChIP sequencing results revealed that DUSP2 and genes in the MAPK signaling pathway are direct targets of NELFCD. ChIP assay verified that PRMT5 is enriched at the promoter region of DUSP2 and that NELFCD overexpression promoted this enrichment. A co-immunoprecipitation assay demonstrated that NELFCD was bound to PRMT5, functioning as a macromolecular complex. CONCLUSIONS: This study suggests that NELFCD promotes the progression of colon cancer by recruiting PRMT5 to inhibit DUSP2 expression, which subsequently activates the p38 signaling pathway. Targeting the NELFCD-DUSP2-p38 signaling axis may be a promising therapeutic intervention for patients suffering from NELFCD-amplified tumors.
Haas DW, etal., J Infect Dis. 2005 Dec 1;192(11):1931-42. Epub 2005 Nov 1.
BACKGROUND: Efavirenz and nelfinavir are metabolized by cytochrome P-450 (CYP) 2B6 and CYP2C19, respectively, with some involvement by CYP3A. Nelfinavir is a substrate for P-glycoprotein, which is encoded by MDR1. The presen
t study examined associations between genetic variants and long-term responses to treatment. METHODS: Adult AIDS Clinical Trials Group study 384 randomized antiretroviral-naive subjects to receive efavirenz and/or nelfinavir plus 2 nucleoside analogues, with follow-up lasting up to 3 years. Population pharmacokinetics were estimated from a nonlinear mixed-effects model. Polymorphisms in CYP2B6, CYP2C19, CYP3A4, CYP3A5, and MDR1 were characterized. RESULTS: The 504 participants in the genetic study included 340 efavirenz recipients and 348 nelfinavir recipients (184 of the 504 participants received both efavirenz and nelfinavir). Of the participants, 49% were white, 31% were black, and 19% were Hispanic. Plasma exposure to efavirenz and nelfinavir in each population was significantly associated with the polymorphisms CYP2B6 516G-->T and CYP2C19 681G-->A, respectively. Among efavirenz recipients, the MDR1 position 3435 TT genotype was associated with decreased likelihood of virologic failure and decreased emergence of efavirenz-resistant virus but not with plasma efavirenz exposure. Among nelfinavir recipients, a trend toward decreased virologic failure was associated with the polymorphism CYP2C19 681G-->A. CONCLUSIONS: Genetic variants predict plasma exposure to efavirenz and nelfinavir, and they may predict virologic failure and/or emergence of drug-resistant virus. These associations with treatment responses must be validated in other studies.
