Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ras (Ha-Ras, Ki-Ras, N-Ras) is implicated in the regulation of various cell functions such as gene expression and cell proliferation downstream from specific extracellular signals. Here, we partially purified a Ras-interacting protein with molecular mass of about 180 kDa (p180) from bovine brain membrane extract by glutathione S-transferase (GST)-Ha-Ras affinity column chromatography. This protein bound to the GTP gamma S (guanosine 5'-(3-O-thio)triphosphate, a nonhydrolyzable GTP analog).GST-Ha-Ras affinity column but not to those containing GDP.GST-Ha-Ras or GTP gamma S.GST-Ha-Ras with a mutation in the effector domain (Ha-RasA38). The amino acid sequences of the peptides derived from p180 were almost identical to those of human AF-6 that is identified as the fusion partner of the ALL-1 protein. The ALL-1/AF-6 chimeric protein is the critical product of the t (6:11) abnormality associated with some human leukemia. AF-6 has a GLGF/Dlg homology repeat (DHR) motif and shows a high degree of sequence similarity with Drosophila Canoe, which is assumed to function downstream from Notch in a common developmental pathway. The recombinant N-terminal domain of AF-6 and Canoe specifically interacted with GTP gamma S.GST-Ha-Ras. The known Ras target c-Raf-1 inhibited the interaction of AF-6 with GTP gamma S.GST-Ha-Ras. These results indicate that AF-6 and Canoe are putative targets for Ras.
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PMID:Identification of AF-6 and canoe as putative targets for Ras. 855 59

A variety of chromosomal translocations to the ALL-1 gene are regularly observed in acute leukemias and are thought to play a key role in the leukemogenic process. Chimeric proteins are encoded by the breakpoint regions of the derivative chromosomes have been proposed to be the relevant oncogenic agents. In addition, internal duplications of the ALL-1 gene have been observed in patients with specific acute myeloid leukemias. Thus, it has been hypothesized that oncogenic variants of the ALL-1 protein may be generated by both chimerization and self-fusion, but the critical structural features endowing the altered proteins with their oncogenic potential are still unknown. Here a novel structural alteration of the ALL-1 gene was observed in three patients presenting with acute T-cell leukemia (ALL) without chromosomal translocations or self-fusions of the ALL-1 gene. These unrelated patients carried an internal deletion in one of the two alleles of the ALL-1 gene that eliminated parts of introns 7 and 8, together with exon 8. The deletion was found in 3 of 74 ALL patients, but not in acute myeloid leukemias, follicular lymphomas, or peripheral blood leukocytes from healthy donors. One ALL patient showed the deletion at diagnosis but no longer at remission or at 9 months after remission. These findings support the hypothesis that the ALL-1 protein may be converted to an oncogenic variant, not only by chimerization or self-fusion, but also by deletion of sequences coded by exon 8. They further suggest that these three different types of structural alterations of the ALL-1 protein may each cause a distinct disease phenotype. Alternatively spliced mRNA species omitting exon 8 were observed in 14 of 24 ALL patients without detectable macroscopic alterations of the ALL-1 gene and also in peripheral blood leukocytes from healthy donors.
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PMID:A specific deletion in the breakpoint cluster region of the ALL-1 gene is associated with acute lymphoblastic T-cell leukemias. 861 68

The acute lymphoblastic leukaemia (ALL)-1 gene on human chromosome 11q23 is the site of many locally clustered chromosomal alterations associated with several types of acute leukaemias, including deletions, partial duplications and translocations. Structurally variant proteins derived from the altered gene presumably cause the malignant transformation of early haemopoietic progenitor cells. According to previously published reports, the gene consisted of at least 21 exons spread over approximately 100 kb. In this report a set of genomic fragments was isolated that represent a total of 35 exons (exons 3-37) encompassing > 95% of the protein-coding region (except exons 1 and 2) and the 3'-non-translated region of the gene. The distances between these exons were determined and a detailed restriction map was produced. The majority of the exon/intron boundaries were sequenced and an intron-phase analysis was performed. The results form the basis for a greater understanding of the translocations and other structural alterations of the gene that conserve the open reading frame and thus produce presumably oncogenic variants of the ALL-1 protein.
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PMID:Exon/intron structure of the human ALL-1 (MLL) gene involved in translocations to chromosomal region 11q23 and acute leukaemias. 870 35