Subscribe to RSS
DOI: 10.1055/s-0032-1331699
Human Eb Peptide: Not just a By-product of Pre-pro-IGF1b Processing?
Publication History
received 13 April 2012
accepted 14 November 2012
Publication Date:
18 January 2013 (online)
![](https://www.thieme-connect.de/media/hmr/201306/lookinside/thumbnails/10.1055-s-0032-1331699-1.jpg)
Abstract
Several physiological activities have been assigned to E-peptides derived from pre-pro-insulin-like growth factor (IGF1) processing; however, the whole range of the E-peptides’ functions is still unknown. The objective of this study was to investigate human Eb peptide (hEb) in terms of its bioactivity, cellular localization, and intracellular trafficking using human cancer cells. Human Eb fused with red fluorescence protein (RFP) or green fluorescence protein (GFP) localizes strongly to nucleoli and to a lesser extent to nuclei of HeLa and U2-OS cells. Mutagenesis of hEb nucleolus localization sequence (NoLS) leads to its partial delocalization from nuclei and nucleoli to cytoplasm of transfected cells. Thus, NoLS is not sufficient for the hEb to be localized in nucleoli of the cells and a different mechanism may be involved in hEb targeting. A BrdU ELISA showed that the proliferation index of cells expressing hEb hybrid proteins increased up to 28%. For comparison, the same assay was performed using HeLa cells treated extracellularly with synthetic hEb. A significant increase in the proliferation index was observed (41–58% for concentrations ranging from 10–100 nM, respectively). Additionally, a cell migration assay was performed using stable U2-OS cell lines expressing hEb fused with RFP or RFP alone as a negative control. The migration index of hEb expressing cells was 38.3% greater. The increase in cell proliferation index and in motile properties of hEb expressing cells demonstrate that hEb is more than a pre-pro-IGF1b processing product, and has intrinsic activity of biological significance.
-
References
- 1 Barton ER. The ABCs of IGF1 isoforms: impact on muscle hypertrophy and implications for repair. Appl Physiol Nutr Metab 2006; 31: 791-797
- 2 Brisson BK, Barton ER. Insulin-like growth factor-1 E-peptide activity is dependent on the IGF1 receptor. PLoS One 2012; 7: e45588
- 3 Kandalla PK, Goldspink G, Butler-Browne G, Mouly V. Mechano Growth Factor E peptide (MGF-E), derived from an isoform of IGF1, activates human muscle progenitor cells and induces an increase in their fusion potential at different ages. Mech Ageing Dev 2011; 132: 154-162
- 4 Matheny Jr RW, Nindl BC, Adamo ML. Minireview: Mechano-growth factor: a putative product of IGF1 gene expression involved in tissue repair and regeneration. Endocrinology 2010; 151: 865-875
- 5 Wallis M. New insulin-like growth factor (IGF)-precursor sequences from mammalian genomes: the molecular evolution of IGFs and associated peptides in primates. Growth Horm IGF Res 2009; 19: 12-23
- 6 Yang S, Goldspink G. Different roles of the IGF1 Ec peptide (MGF) and mature IGF1 in myoblast proliferation and differentiation. FEBS Lett 2002; 522: 156-160
- 7 Mills P, Dominique JC, Lafrenière JF, Bouchentouf M, Tremblay JP. A synthetic mechano growth factor E Peptide enhances myogenic precursor cell transplantation success. Am J Transplant 2007; 7: 2247-2259
- 8 Siegfried JM, Kasprzyk PG, Treston AM, Mulshine JL, Quinn KA, Cuttitta F. A mitogenic peptide amide encoded within the E peptide domain of the insulin-like growth factor IB prohormone. Proc Natl Acad Sci USA 1992; 89: 8107-8111
- 9 Chen MJ, Chiou PP, Lin P, Lin CM, Siri S, Peck K, Chen TT. Suppression of growth and cancer-induced angiogenesis of aggressive human breast cancer cells (MDA-MB-231) on the chorioallantoic membrane of developing chicken embryos by E-peptide of pro-IGF1. J Cell Biochem 2007; 101: 1316-1327
- 10 Nicholas KB, Nicholas HB. GenDoc: A tool for editing and ad notating multiple alignments. 1997 version 2.5
- 11 Liu HS, Jan MS, Chou CK, Chen PH, Ke NJ. Is green fluorescent protein toxic to the living cells?. Biochem Biophys Res Commun 1999; 260: 712-717
- 12 Zisa D, Shabbir A, Mastri M, Suzuki G, Lee T. Intramuscular VEGF repairs the failing heart: role of host-derived growth factors and mobilization of progenitor cells. Am J Physiol Regul Integr Comp Physiol 2009; 297: R1503-R1515
- 13 Dowling JJ, Vreede AP, Kim S, Golden J, Feldman EL. Kindlin-2 is required for myocyte elongation and is essential for myogenesis. BMC Cell Biol 2008; 9: 36
- 14 Tan DS, Cook A, Chew SL. Nucleolar localization of an isoform of the IGF1 precursor. BMC Cell Biol 2002; 3: 17
- 15 Tan KP, Shih KN, Lo SJ. Ser-123 of the large antigen of hepatitis delta virus modulates its cellular localization to the nucleolus, SC-35 speckles or the cytoplasm. J Gen Virol 2004; 85: 1685-1694
- 16 Pederson T. Growth factors in the nucleolus?. J Cell Biol 1998; 143: 279-281
- 17 Lam YW, Trinkle-Mulcahy L, Lamond AI. The nucleolus. J Cell Sci 2005; 118: 1335-1337
- 18 Boisvert FM, van Koningsbruggen S, Navascués J, Lamond AI. The multifunctional nucleolus. Nat Rev Mol Cell Biol 2007; 8: 574-585
- 19 Lindahl E, Nyman U, Melles E, Sigmundsson K, Ståhlberg M, Wahren J, Obrink B, Shafqat J, Joseph B, Jörnvall H. Cellular internalization of proinsulin C-peptide. Cell Mol Life Sci 2007; 64: 479-486
- 20 Scott MS, Boisvert FM, McDowall MD, Lamond AI, Barton GJ. Characterization and prediction of protein nucleolar localization sequences. Nucleic Acids Res 2010; 38: 7388-7399
- 21 Carmo-Fonseca M, Mendes-Soares L, Campos I. To be or not to be in the nucleolus?. Nat Cell Biol 2000; 2: 107-112
- 22 Lindahl E, Nyman U, Zaman F, Palmberg C, Cascante A, Shafqat J, Takigawa M, Sävendahl L, Jörnvall H, Joseph B. Proinsulin C-peptide regulates ribosomal RNA expression. J Biol Chem 2010; 285: 3462-3469
- 23 Kuo YH, Chen TT. Novel activities of pro-IGF1 E peptides: regulation of morphological differentiation and anchorage-independent growth in human neuroblastoma cells. Experimental Cell Research 2002; 280: 75-89
- 24 Mills P, Lafrenière JF, Benabdallah BF, Fahime El MEl, Tremblay JP. A new pro-migratory activity on human myogenic precursor cells for a synthetic peptide within the E domain of the mechano growth factor. Exp Cell Res 2007; 313: 527-537
- 25 Jozefiak A, Pacholska-Bogalska J, Myga-Nowak M, Kedzia W, Kwasniewska A, Luczak M, Kedzia H, Gozdzicka-Jozefiak A. A Serum and tissue levels of insulin-like growth factor-I in women with dysplasia and HPV-positive cervical cancer. Mol Med Report 2008; 1: 231-237