Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human Elongator complex was purified to virtual homogeneity from HeLa cell extracts. The purified factor can exist in two forms: a six-subunit complex, holo-Elongator, which has histone acetyltransferase activity directed against histone H3 and H4, and a three-subunit core form, which does not have histone acetyltransferase activity despite containing the catalytic Elp3 subunit. Elongator is a component of early elongation complexes formed in HeLa nuclear extracts and can interact directly with RNA polymerase II in solution. Several human homologues of the yeast Elongator subunits were identified as subunits of the human Elongator complex, including StIP1 (STAT-interacting protein 1) and IKAP (IKK complex-associated protein). Mutations in IKAP can result in the severe human disorder familial dysautonomia, raising the possibility that this disease might be due to compromised Elongator function and therefore could be a transcription disorder.
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PMID:Purification and characterization of the human elongator complex. 1171 25

Familial dysautonomia (FD) is the best-known and most common member of a group of congenital sensory/autonomic neuropathies characterized by widespread sensory and variable autonomic dysfunction. As opposed to the sensory/motor neuropathies, little is known about the causes of neuronal dysfunction and loss in the sensory/autonomic neuropathies. FD involves progressive neuronal degeneration, has a broad impact on the operation of many of the body's systems, and leads to a markedly reduced quality of life and premature death. In 2001, we identified two mutations in the IKBKAP gene that result in FD. IKBKAP encodes IKAP, a member of the putative human holo-Elongator complex, which may facilitate transcription by RNA polymerase II. Whether or not the Elongator plays this role is moot. The FD mutation found on >99.5% of FD chromosomes does not cause complete loss of function. Instead, it results in a tissue-specific decrease in splicing efficiency of the IKBKAP transcript; cells from patients retain some capacity to produce normal mRNA and protein. To better understand the relationship between the genotype of FD patients and their phenotype, we have used in situ hybridization histochemistry to map the IKAP mRNA in sections of whole rat embryos. The mRNA is widely distributed. Highest levels are in the nervous system, but substantial amounts are also present in peripheral organs.
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PMID:Of splice and men: what does the distribution of IKAP mRNA in the rat tell us about the pathogenesis of familial dysautonomia? 1291 82

Familial dysautonomia (FD) is a developmental neuropathy of the sensory and autonomous nervous systems. The IKBKAP gene, encoding the IKAP/hELP1 subunit of the RNA polymerase II Elongator complex is mutated in FD patients, leading to a tissue-specific mis-splicing of the gene and to the absence of the protein in neuronal tissues. To elucidate the function of IKAP/hELP1 in the development of neuronal cells, we have downregulated IKBKAP expression in SHSY5Y cells, a neuroblastoma cell line of a neural crest origin. We have previously shown that these cells exhibit abnormal cell adhesion when allowed to differentiate under defined culture conditions on laminin substratum. Here, we report results of a microarray expression analysis of IKAP/hELP1 downregulated cells that were grown on laminin under differentiation or non-differentiation growth conditions. It is shown that under non-differentiation growth conditions, IKAP/hELP1 downregulation affects genes important for early developmental stages of the nervous system, including cell signaling, cell adhesion and neural crest migration. IKAP/hELP1 downregulation during differentiation affects the expression of genes that play a role in late neuronal development, in axonal projection and synapse formation and function. We also show that IKAP/hELP1 deficiency affects the expression of genes involved in calcium metabolism before and after differentiation of the neuroblastoma cells. Hence, our data support IKAP/hELP1 importance in the development and function of neuronal cells and contribute to the understanding of the FD phenotype.
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PMID:Effects of IKAP/hELP1 deficiency on gene expression in differentiating neuroblastoma cells: implications for familial dysautonomia. 2155 66