Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The sno gene cluster in Streptomyces nogalater ATCC 27451 contains the nogalamycin biosynthesis genes. A set of plasmid constructions carrying fragments of the sno cluster that lie downstream of snoD were used to complement the S. galilaeus mutant H039, which is blocked in rhodosamine and 2-deoxyfucose biosynthesis in the aclacinomycin pathway. Sequence analysis of this cluster revealed three contiguous open reading frames (ORFs) that were designated snoF, snoG, and snoH. Only those plasmid constructs that expressed SnoG were able to complement H039. SnoG shows similarity to GalE, a UDP-glucose-4-epimerase catalyzing the epimerization of UDP-glucose to UDP-galactose. The putative SnoF protein is similar to 3,5-epimerases involved in rhamnose biosynthesis. The deduced product of snoH is a 489-amino acid polypeptide. It is similar to the product of dau ORF3 found in the daunomycin cluster. However its function is still unclear. Based on the complementation experiments and sequence analysis, this part of the sno cluster is suggested to be involved in the biosynthesis of the sugar portion of nogalamycin. Interestingly, SnoA, a transcriptional activator for the sno minimal polyketide synthase, is also needed to express this cluster.
 ...
PMID:Characterization of Streptomyces nogalater genes encoding enzymes involved in glycosylation steps in nogalamycin biosynthesis. 934 12

The proteins SKI and SnoN are implicated in processes as diverse as differentiation, transformation and tumor progression. Until recently, SKI was solely viewed as a nuclear protein with a principal function of inhibiting TGF-beta signaling through its association with the Smad proteins. However, new studies suggest that SKI plays additional roles not only inside but also outside the nucleus. In normal melanocytes and primary non-invasive melanomas, SKI localizes predominantly in the nucleus, whereas in primary invasive melanomas SKI displays both nuclear and cytoplasmic localization. Intriguingly, metastatic melanoma tumors display nuclear and cytoplasmic or predominantly cytoplasmic SKI distribution. Cytoplasmic SKI is functional, as it associates with Smad3 and prevents its nuclear localization mediated by TGF-beta. SKI can also function as a transcriptional activator, targeting the beta -catenin pathway and activating MITF and NrCAM, two proteins involved in survival, migration and invasion. Intriguingly, SKI appears to live a dual life, one as a tumor suppressor and another as a transforming protein. Loss of one copy of mouse ski increases susceptibility to tumorigenesis in mice, whereas its overexpression is associated with cancer progression of human melanoma, esophageal, breast and colon. The molecular reasons for such dramatic change in SKI function appear to result from new acquired activities. In this review, we discuss the mechanisms by which SKI regulates crucial pathways involved in the progression of human malignant melanoma.
 ...
PMID:SKI pathways inducing progression of human melanoma. 1598 36

The leukemia-associated protein EVI1 possesses seven zinc fingers within an N-terminal domain (amino acids 1-250) that binds to GACAAGATA. Single amino acid missense mutants of EVI1 were developed that failed to bind DNA either in vitro, as assessed by gel shift assay, or in vivo, as shown by transactivation studies. Specifically, mutation R205N lacks high affinity binding to the GACAAGATA motif. Putative EVI1 target genes were identified by using an EVI1-(1-250)-VP16 fusion protein that acts as a transcriptional activator with the binding specificity of EVI1. Sixteen genes induced in NIH 3T3 cells by wild type EVI1-VP16 but not by mutant forms were identified. Sequence analysis revealed evolutionarily conserved GACAAGATA-like motifs within 10 kb of their transcription start sites, and by chromatin immunoprecipitation in fibroblasts, we showed occupancy of many of these sites by EVI1-VP16. To assess whether native EVI1 binds to these sites in EVI1-transformed myeloid cells, we performed chromatin immunoprecipitation in 32Dcl3 and NFS58 cells, using anti-EVI1 antisera, and we showed that the majority of these sites is bound by wild type EVI1. These putative target genes include Gadd45g, Gata2, Zfpm2/Fog2, Skil (SnoN), Klf5 (BTEB2), Dcn, and Map3k14 (Nik). In this study we demonstrated for the first time that the N-terminal DNA binding domain of EVI1 has the capacity to bind to endogenous genes. We hypothesized that these genes play a critical role in EVI1-induced transformation.
 ...
PMID:Identification of binding sites of EVI1 in mammalian cells. 1600 53