These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: The family of hepatoma-derived growth factor proteins: characterization of a new member HRP-4 and classification of its subfamilies.
    Author: Dietz F, Franken S, Yoshida K, Nakamura H, Kappler J, Gieselmann V.
    Journal: Biochem J; 2002 Sep 01; 366(Pt 2):491-500. PubMed ID: 12006088.
    Abstract:
    Hepatoma-derived growth factor (HDGF)-related proteins (HRPs) comprise a family of polypeptides named after HDGF, which was identified by its mitogenic activity towards fibroblasts. In the present study, we describe a hitherto unknown HRP, termed HRP-4. The cDNA of bovine HRP-4 (bHRP-4) predicts a polypeptide of 235 amino acids. Northern- and Western-blot analyses of various bovine tissues demonstrated that HRP-4 is only expressed in the testis. Recombinantly produced bHRP-4 and murine HDGF (mHDGF) histidine-tagged polypeptides display growth-factor activity for cultured primary human fibroblasts at an optimum concentration of 1 ng/ml in serum-free medium. The growth-factor activity declines with increasing concentrations to reach background levels at 1 microg/ml. The expression of the fusion proteins, bHRP-4-green fluorescent protein and mHDGF-green fluorescent protein, in HEK-293 cells demonstrates nuclear localization of the proteins. bHRP-4 and mHDGF bind to the glycosaminoglycans heparin and heparan sulphate, but not to chondroitin sulphate. Affinity constants determined for these interactions are between 6 and 42 nM. Comparison of the bHRP-4 amino acid sequence with HRP-1-3 and p52/75/lens epithelium-derived growth factor (LEDGF) shows that these proteins share a conserved N-terminal part of 91 amino acids but have C-termini of different lengths and charge. This demonstrates the modular structure of these proteins and allows its classification into three groups based on charge, size and sequence comparison. HRP-4, HRP-1 and HDGF are small acidic proteins, HRP-3 is a small basic protein, and HRP-2 and p52/75/LEDGF are larger basic proteins.
    [Abstract] [Full Text] [Related] [New Search]