Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q9UID6 (Kruppel-like)
 147 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Wound repair in the liver induces altered gene expression in stellate cells (resident mesenchymal cells) in a process known as "activation." A zinc finger transcription factor cDNA, zf9, was cloned from rat stellate cells activated in vivo. Zf9 expression and biosynthesis are increased markedly in activated cells in vivo compared with cells from normal rats ("quiescent" cells). The factor is localized to the nucleus and the perinuclear zone in activated but not quiescent cells. Zf9 mRNA also is expressed widely in nonhepatic adult rat tissues and the fetal liver. The zf9 nucleotide sequence predicts a member of the Kruppel-like family with a unique N-terminal domain rich in serine-proline clusters and leucines. The human zf9 gene maps to chromosome 10P near the telomere. Zf9 binds specifically to a DNA oligonucleotide containing a GC box motif. The N-terminal domain of Zf9 (amino acids 1-201) is transactivating in the chimeric GAL4 hybrid system. In Drosophila schneider cells, full length Zf9 transactivates a reporter construct driven by the SV40 promoter/enhancer, which contains several GC boxes. A physiologic role for Zf9 is suggested by its transactivation of a collagen alpha1(I) promoter reporter. Transactivation of collagen alpha1(I) by Zf9 is context-dependent, occurring strongly in stellate cells, modestly in Hep G2 cells, and not at all in D. schneider cells. Our results suggest that Zf9 may be an important signal in hepatic stellate cell activation after liver injury.
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PMID:Zf9, a Kruppel-like transcription factor up-regulated in vivo during early hepatic fibrosis. 968 9

Leukotriene C(4) synthase (LTC(4)S) is responsible for the biosynthesis of cysteinyl leukotrienes that participate in allergic and asthmatic inflammation. We analyzed 2.1 kilobases of the 5'-flanking region of the human LTC(4)S gene, which contains three DNase I hypersensitivity sites, for its transcriptional activity when fused to a promoterless and enhancerless luciferase gene. Deletion analysis revealed a nonspecific basal promoter region between nucleotides -122 and -56 upstream of the translation start site which contains a consensus Sp1 binding site and a putative initiator element (Inr) and cell-specific enhancer regions further upstream. A single mutation of either the Sp1 binding site between nucleotides -120 and -115 or the Inr (CAGAC) between nucleotides -66 and -62 reduced the expression of the reporter gene by approximately 60%, whereas double mutations decreased the expression by approximately 80%. The incubation of nuclear extracts from THP-1 and K562 cells with a (32)P-labeled oligonucleotide containing the Sp1 site or the Inr sequence gave gel-shifted complexes that were blocked by their respective cold oligonucleotides, and antisera specific for Sp1 and Sp3 provided supershifts for the former. Linker-scanning mutations of a cell-specific regulatory region revealed that mutations from nucleotides -165 to -125 reduced reporter activity. This region contains a tandem CACCC repeat (at nucleotides -149 to -145 and -139 to -135). An oligonucleotide containing the distal CACCC motif was gel shifted by THP-1 cell nuclear extract and was supershifted by antisera to Sp1 and Sp3. Cotransfection of an Sp1 expression plasmid into Drosophila SL2 cells with a -228 to -3 LTC(4)S reporter construct transactivated the reporter gene, whereas mutations at the CACCC repeat region reduced Sp1 transactivation by approximately 66%. Similarly, the Kruppel-like factor Zf9/CPBP (core promoter-binding protein) transactivated the -228 construct in COS cells but not its CACCC mutant construct. These findings indicate the involvement of Sp1 and an Inr in non-cell-specific regulation and a Kruppel-like transcription factor and Sp1 in the cell-specific regulation of the LTC(4)S gene. These are the first such analyses of a member of a newly recognized superfamily of membrane-associated proteins involved in eicosanoid and glutathione metabolism, which contains key proteins involved in the generation of both prostanoids and cysteinyl leukotrienes.
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PMID:Cell-specific transcription of leukotriene C(4) synthase involves a Kruppel-like transcription factor and Sp1. 1072 37

Kruppel-like factor 6 (KLF6/Zf9/CPBP), a member of the Kruppel-like family of zinc finger transcription factors, has recently been suggested to be a mutated tumor suppressor in selected human cancers. Initially, we investigated whether the KLF6 gene was altered in 36 paired non-small cell lung cancers (NSCLC), 89 brain tumors, 7 normal brains, 46 cancer cell lines from a large variety of tissues, and 144 peripheral blood cells from healthy individuals using single strand conformation polymorphism (PCR-SSCP) and DNA sequencing. Changes in the coding region of KLF6 were found in brain tumors (missense changes, 8%; silent polymorphisms, 2%), lung cancers (missense changes, 3%; silent polymorphisms, 6%) and cancer cell lines (missense changes, 2%; silent polymorphisms, 2%). All of the nucleotide changes in the lung tumor samples were present in their matched normal samples, suggesting that these changes were germline polymorphism. Many of the altered KLF6 genes found in the brain tumors were cloned into an expression vector and placed into a GBM cell line, and cell growth was monitored. Wild-type, deleted exon 3, or E30G missense KLF6 significantly reduced cell growth; in contrast, forced expression of KLF6 having either the S92R, P183L or A276G missense substitution did not alter the growth of transfected GBM cells (p > 0.05). Expression levels of KLF6 were higher in normal brain samples than in glioma samples as measured by real-time RT-PCR (p < 0.05). To our surprise, nucleotide changes were found at -4, -5, and -6 upstream of the start of translation in 45% of brain tumors, and 10% of normal blood samples. Focusing on the most frequent alteration (-4 C > A), the nucleotide change did not affect translation of KLF6. Taking together, KLF6 coding sequences are altered in 10% brain tumors, 8% NSLC, and 4% of cancer cell lines. All of those observed in lung cancer are germline polymorphisms. Several additional ones identified in GBM, have lost their ability to slow the growth of glioma cells; furthermore, a proportion of GBM have decreased expression of KLF6 as compared to normal brain tissue. Dysfunction of this gene may contribute to oncogenesis in the brain.
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PMID:KLF6: mutational analysis and effect on cancer cell proliferation. 1714 13