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

Water channel aquaporin-1 (AQP1) is expressed in erythrocytes and various epithelia and endothelia. To study AQP1 gene regulation, human cell lines were screened for inducible AQP1 expression. Human erythroleukemia HEL cells showed AQP1 transcript expression on RNase protection assay. After butyrate-induced erythroid differentiation, AQP1 transcript expression increased strongly, producing water-permeable cells with plasma membrane localization of immunoreactive AQP1. In addition, a clonal subline of K562 cells [K562(S)] showed strong butyrate-induced expression of functional AQP1. A 1.8-kb DNA fragment of the 5' flanking region of the human AQP1 gene was isolated, sequenced, and analyzed functionally by the CAT reporter assay. The AQP1 promoter contained TATA and CCAAT boxes; Sp1, AP1, AP2, and E-box elements; and erythrocyte-specific CACCC and Kruppel-like (CCCCACCCA) elements. AQP1 promoter activity was more than 24-fold higher in HEL and K562(S) cells than in nonerythroid (HeLa) cells, indicating the presence of erythroid-specific factors. In K562(S) cells, CAT activities for promoter fragments to bp +23 [relative to beta-gal and normalized to 100% for the plasmid CP-282 (bp -282 to +23)] were 22 (-1779), 73 (-1402), 61 (-1129), 31 (-789), 87 (-487), 100 (-282), 73 (-229), 52 (-152), and 60% (-79). After butyrate-induced differentiation, CAT activities were stimulated approximately 10-fold for constructs -229/+23 and longer, compared to approximately 5-fold for -152/+23 and -79/+23; glucocorticoids did not affect CAT activities. These results suggest a basis for erythroid-specific AQP1 expression and the presence of a butyrate-response sequence involved in inducible AQP1 regulation in erythroleukemia cells.
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PMID:Isolation of the human aquaporin-1 promoter and functional characterization in human erythroleukemia cell lines. 948 Jul 47

Erythroid Kruppel-like Factor (EKLF) is an erythroid-specific transcription factor that plays a critical role in gamma- to beta-globin gene switching during development. To identify essential domains required for EKLF transactivation function, we cotransfected a human erythroleukemia cell line (K562) with a locus control region gamma/Luc-beta/Cat reporter and an EKLF expression vector. In this assay EKLF mediates a 500-fold induction of beta/CAT expression compared with controls. To map essential transactivation domains, progressive NH(2)-terminal and internal deletion mutants of EKLF were constructed. All EKLF mutants were expressed at wild-type levels, localized to the nucleus, and bound DNA. When mutant EKLF proteins were tested for beta/CAT activation, a novel transactivation domain was identified. This novel domain, encompassing amino acids (aa) 140-358, is sufficient for maximal beta/CAT activation. An 85-amino acid subdomain within this region (aa 140-225) is essential for its activity. Interestingly, this central transactivation subdomain is functionally redundant with the amino-terminal domain (aa 1-139). Thus, EKLF possesses at least two potent transactivation domains that appear to function in a redundant manner.
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PMID:Novel transactivation domain in erythroid Kruppel-like factor (EKLF). 1109 87

We isolated by low strigency screening of a human erythroleukemia cDNA library (K562) 45 indipendent clones hybridizing to a Kruppel-like (HF.10) zinc finger cDNA. The expression of 15 such cDNAs in human hematopoietic cell lines was investigated. Preliminary sequence analysis of the zinc finger motifs in these cDNAs indicate that they belong to a subclass of the Cys-Cys/His-His motif, showing the highest homology to the Wilm's tumor and EGR1, EGR2 cDNAs.
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PMID:Characterization of a subfamily of zinc finger genes expressed in human hematopoietic cell lines. 2235 56