Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0032463 (polycythemia vera)
 3,374 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new abnormal hemoglobin, Hb J Amiens beta 17 (A 14) Lys replaced by Asn, has been discovered during the exploration of a recent polycythemia in a 65-year-old patient of Spanish extraction. Oxygen affinity of washed red blood cells was found to be normal at pH 7.13 (P 50 = 30.0 mmHg, N = 29.5 +/- 1). Cooperativity is unchanged, and no instability was detected. From this study, it is concluded that there is no relation between this functionally silent hemoglobin and the polycythemia. In fact, the recent appearance of the polycythemia, the involvement of the other blood cell lines, particularly the thrombocytosis, the high score of leukocyte alkaline phosphatases, and the results of the bone marrow biopsy led to the diagnosis of polycythemia vera.
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PMID:[Hemoglobin J Amiens beta 17 (A 14) Lys replaced by Asn. Coincidence of a functionally silent new abnormal hemoglobin and a polycythemia vera (author's transl)]. 12 38

An abnormal hemoglobin was suspected in a 70-year-old Japanese male with cerebral infarction and erythremia with high performance liquid chromatography assay of Hb A1c. The hemoglobin variant migrated to the anode more rapidly than Hb A. Structure determination studies, including amino acid analysis of the abnormal peptide and DNA sequencing of a partially cloned alpha-globin gene, demonstrated that it is a new hemoglobin variant which has been named Hb Kanagawa [alpha 40(C5)Lys----Met]. This variant showed an increased oxygen affinity, decreased heme-heme interaction, and a lowered 2,3-diphosphoglycerate effect relative to normal.
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PMID:Hb Kanagawa [alpha 40(C5)Lys----Met]: a new alpha chain variant with an increased oxygen affinity. 163 55

The JAK2 V617F mutation present in over 95% of Polycythemia Vera patients and in 50% of Essential Thrombocythemia and Primary Myelofibrosis patients renders the kinase constitutively active. In the absence of a three-dimensional structure for the full-length protein, the mechanism of activation of JAK2 V617F has remained elusive. In this study, we used functional mutagenesis to investigate the involvement of the JH2 alphaC helix in the constitutive activation of JAK2 V617F. We show that residue F595, located in the middle of the alphaC helix of JH2, is indispensable for the constitutive activity of JAK2 V617F. Mutation of F595 to Ala, Lys, Val or Ile significantly decreases the constitutive activity of JAK2 V617F, but F595W and F595Y are able to restore it, implying an aromaticity requirement at position 595. Substitution of F595 to Ala was also able to decrease the constitutive activity of two other JAK2 mutants, T875N and R683G, as well as JAK2 K539L, albeit to a lower extent. In contrast, the F595 mutants are activated by erythropoietin-bound EpoR. We also explored the relationship between the dimeric conformation of EpoR and several JAK2 mutants. Since residue F595 is crucial to the constitutive activation of JAK2 V617F but not to initiation of JAK2 activation by cytokines, we suggest that small molecules that target the region around this residue might specifically block oncogenic JAK2 and spare JAK2 wild-type.
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PMID:JAK2 V617F constitutive activation requires JH2 residue F595: a pseudokinase domain target for specific inhibitors. 2058 91