Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q06643 (non-Hodgkin's lymphoma)
 11,307 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Anaplastic Lymphoma Kinase (ALK) was originally identified as a member of the insulin receptor subfamily of receptor tyrosine kinases that acquires transforming capability when truncated and fused to nucleophosmin (NPM) in the t(2;5) chromosomal rearrangement associated with non-Hodgkin's lymphoma, but further insights into its normal structure and function are lacking. Here, we characterize a full-length normal human ALK cDNA and its product, and determine the pattern of expression of its murine homologue in embryonic and adult tissues as a first step toward the functional assessment of the receptor. Analysis of the 6226 bp ALK cDNA identified an open reading frame encoding a 1620-amino acid (aa) protein of predicted mass approximately 177 kDa that is most closely related to leukocyte tyrosine kinase (LTK), the two exhibiting 57% aa identity and 71% similarity over their region of overlap. Biochemical analysis demonstrated that the approximately 177 kDa ALK polypeptide core undergoes co-translational N-linked glycosylation, emerging in its mature form as a 200 kDa single chain receptor. Surface labeling studies indicated that the 200 kDa glycoprotein is exposed at the cell membrane, consistent with the prediction that ALK serves as the receptor for an unidentified ligand(s). In situ hybridization studies revealed Alk expression beginning on embryonic day 11 and persisting into the neonatal and adult periods of development. Alk transcripts were confined to the nervous system and included several thalamic and hypothalamic nuclei; the trigeminal, facial, and acoustic cranial ganglia; the anterior horns of the spinal cord in the region of the developing motor neurons; the sympathetic chain; and the ganglion cells of the gut. Thus, ALK is a novel orphan receptor tyrosine kinase that appears to play an important role in the normal development and function of the nervous system.
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PMID:ALK, the chromosome 2 gene locus altered by the t(2;5) in non-Hodgkin's lymphoma, encodes a novel neural receptor tyrosine kinase that is highly related to leukocyte tyrosine kinase (LTK) 917 53

The anaplastic lymphoma kinase gene (ALK) is a gene on chromosome 2p23 that has expression restricted to the brain, testis and small intestine but is not expressed in normal lymphoid tissue. It has similarity to the insulin receptor subfamily of kinases and is emerging as having increased pathologic and potential therapeutic importance in malignant disease. This gene was originally established as being implicated in the pathogenesis of rare diseases including inflammatory myofibroblastic tumour (IMT) and ALK-positive anaplastic large cell lymphoma, which is a subtype of non-Hodgkin's lymphoma. Recently the number of diseases in which ALK is implicated in their pathogenesis has increased. In 2007, an inversion of chromosome 2 involving ALK and a fusion partner gene in a subset of non-small cell lung cancer was discovered. In 2008, publications emerged implicating ALK in familial and sporadic cases of neuroblastoma, a childhood cancer of the sympatho-adrenal system. Chromosomal abnormalities involving ALK are translocations, amplifications or mutations. Chromosomal translocations are the longest recognised ALK genetic abnormality. When translocations occur a fusion gene is created between ALK and a gene partner. This has been described in ALK-positive anaplastic large cell lymphoma in which ALK is fused to NPM (nucleolar protein gene) and in non-small cell lung cancer where ALK is fused to EML4 (Echinoderm microtubule-associated protein 4). The most frequently described partner genes in inflammatory myofibroblastic tumour are tropomyosin 3/4 (TMP3/4), however in IMTs a diversity of ALK fusion partners have been found, with the ability to homodimerise a common characteristic. Point mutations and amplification of the ALK gene occur in the childhood cancer neuroblastoma. Therapeutic targeting of ALK fusion genes using tyrosine kinase inhibition, vaccination using an ALK specific antigen and treatment using viral vectors for RNAi are emerging potential therapeutic possibilities.
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PMID:The emerging pathogenic and therapeutic importance of the anaplastic lymphoma kinase gene. 2045 71

ALK (anaplastic lymphoma kinase) is an RTK (receptor tyrosine kinase) of the IRK (insulin receptor kinase) superfamily, which share an YXXXYY autophosphorylation motif within their A-loops (activation loops). A common activation and regulatory mechanism is believed to exist for members of this superfamily typified by IRK and IGF1RK (insulin-like growth factor receptor kinase-1). Chromosomal translocations involving ALK were first identified in anaplastic large-cell lymphoma, a subtype of non-Hodgkin's lymphoma, where aberrant fusion of the ALK kinase domain with the NPM (nucleophosmin) dimerization domain results in autophosphosphorylation and ligand-independent activation. Activating mutations within the full-length ALK kinase domain, most commonly R1275Q and F1174L, which play a major role in neuroblastoma, were recently identified. To provide a structural framework for understanding these mutations and to guide structure-assisted drug discovery efforts, the X-ray crystal structure of the unphosphorylated ALK catalytic domain was determined in the apo, ADP- and staurosporine-bound forms. The structures reveal a partially inactive protein kinase conformation distinct from, and lacking, many of the negative regulatory features observed in inactive IGF1RK/IRK structures in their unphosphorylated forms. The A-loop adopts an inhibitory pose where a short proximal A-loop helix (alphaAL) packs against the alphaC helix and a novel N-terminal beta-turn motif, whereas the distal portion obstructs part of the predicted peptide-binding region. The structure helps explain the reported unique peptide substrate specificity and the importance of phosphorylation of the first A-loop Tyr1278 for kinase activity and NPM-ALK transforming potential. A single amino acid difference in the ALK substrate peptide binding P-1 site (where the P-site is the phosphoacceptor site) was identified that, in conjunction with A-loop sequence variation including the RAS (Arg-Ala-Ser)-motif, rationalizes the difference in the A-loop tyrosine autophosphorylation preference between ALK and IGF1RK/IRK. Enzymatic analysis of recombinant R1275Q and F1174L ALK mutant catalytic domains confirms the enhanced activity and transforming potential of these mutants. The transforming ability of the full-length ALK mutants in soft agar colony growth assays corroborates these findings. The availability of a three-dimensional structure for ALK will facilitate future structure-function and rational drug design efforts targeting this receptor tyrosine kinase.
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PMID:Crystal structure of the ALK (anaplastic lymphoma kinase) catalytic domain. 2063 93