Protein HMG-17 is hyper-expressed in rat glucagonoma. Single-step isolation and sequencing.
High-mobility-group protein 17 (HMG-17) was identified by reversed-phase high-performance liquid chromatography analysis as a major component in acidic extracts of transplantable rat glucagonoma tissue but not in insulinoma tissue of similar origin. The peptide was purified in a single step and the entire sequence of 89 amino acids was determined. Rat HMG-17 has a molecular mass of 9238 Da and shows strong similarity to human, bovine (94.4%) and chicken (88.8%) HMG-17. Six of the seven residues which vary among the mammalian sequences are located within a short segment (positions 64-83) present in the acidic, non-DNA-binding C-terminal part of HMG-17. This region shows least similarity to the otherwise related proteins HMG-14 and H6 (a trout HMG protein). Interestingly, four of the six variable positions are Asp in rat HMG-17 which results in an overall net increase in the negative charge of the C-terminal region. The nature of selective hyper-expression of HMG-17 in glucagon but not in insulin-producing tumor tissue remains to be clarified.
Nielsen
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E
Hagedorn Research Laboratory, Gentofte, Denmark.
Welinder
B
B
Madsen
O D
OD
D007516:Adenoma, Islet Cell / Q000032:analysis*; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002645:Chickens; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D015870:Gene Expression; D005935:Glucagonoma / Q000032:analysis* / Q000235:genetics; D006609:High Mobility Group Proteins / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008969:Molecular Sequence Data; D010190:Pancreatic Neoplasms / Q000032:analysis* / Q000235:genetics; D051381:Rats; D012689:Sequence Homology, Nucleic Acid
D006609:High Mobility Group Proteins