Interaction of high-molecular-weight basic fibroblast growth factor with endothelium: Biological activity and intracellular fate of human recombinant Mr 24,000 bFGF

A. Gualandris, C. Urbinati, M. Rusnati, M. Ziche, M. Presta

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

The single-copy gene of human basic fibroblast growth factor (bFGF) encodes four co-expressed isoforms, with an apparent molecular weight (Mr) of 24 kD, 22.5 kD, 22 kD, and 18 kD, co-translated from a single mRNA. As a tool for the study of the role exerted by the different bFGF isoforms in the biology of endothelial cells, human recombinant 24-kD bFGF was produced and purified from transformed Escherichia coli cells. To this purpose, the novel CUG start codon present in human bFGF cDNA and responsible for the synthesis of 24-kD bFGF was mutaC genized to the classic AUG start codon. Transient expression of the mutagenized cDNA in simian COS-1 cells, followed by immunolocalization and subcellular fractionation, resulted in the synthesis of high levels of 24-kD bFGF, which localizes in the cell nucleus as an intact protein. When the same 24-kD bFGF cDNA was expressed in E. coli, the recombinant protein was purified to homogeneity by heparin-Sepharose and ion-exchange chromatography. Recombinant 24-kD bFGF was similar to recombinant 18-kD bFGF in receptor-binding activity and in inducing cell proliferation, plasminogen activator production, and chemotactic movement in cultured endothelial cells. In agreement with the in vitro observations, 24-kD bFGF and 18-kD bFGF exerted a similar angiogenic response when assayed in vivo in the rabbit cornea. Experiments performed with the radiolabeled molecule demonstrated that 24-kD bFGF has an intrinsic ability to bind to high-affinity receptors when added to endothelial GM 7373 cell cultures. Receptor-bound 24-kD bFGF is internalized within the cell and associates with the nucleus with kinetics similar to 18-kD bFGF. Internalized 24-kD bFGF is first processed to the 18-kD form via a chloroquine-insensitive pathway and then to smaller fragments into the lysosomal compartment. At variance with the data obtained in transfected COS-1 cells, only limited amounts of exogenous internalized 24-kD bFGF associates with the nucleus in the intact form, mostly of the nuclear-bound molecule being represented by the processed 18-kD protein and by smaller degradation products. In conclusion, human recombinant 24-kD bFGF exerts a biological response in endothelial cells similar to 18-kD bFGF both in vitro and in vivo. Our data point to a different intracellular behavior of the high-molecular-weight bFGF isoform when added exogenously to cultured cells or when produced endogenously in transfected cells.

Original languageEnglish
Pages (from-to)149-159
Number of pages11
JournalJournal of Cellular Physiology
Volume161
Issue number1
Publication statusPublished - Oct 1994

Fingerprint

Fibroblast Growth Factor 2
Bioactivity
Endothelium
Molecular Weight
Molecular weight
Endothelial cells
Protein Isoforms
Initiator Codon
Endothelial Cells
Complementary DNA
COS Cells
Escherichia coli
Cultured Cells
Cells
Fibroblast Growth Factor Receptors
Molecules
Aptitude
Plasminogen Activators
Escherichia coli Proteins
Ion Exchange Chromatography

ASJC Scopus subject areas

  • Cell Biology
  • Clinical Biochemistry
  • Physiology

Cite this

Interaction of high-molecular-weight basic fibroblast growth factor with endothelium : Biological activity and intracellular fate of human recombinant Mr 24,000 bFGF. / Gualandris, A.; Urbinati, C.; Rusnati, M.; Ziche, M.; Presta, M.

In: Journal of Cellular Physiology, Vol. 161, No. 1, 10.1994, p. 149-159.

Research output: Contribution to journalArticle

@article{1cc4e594dccb4a6f8774620c0a115b6c,
title = "Interaction of high-molecular-weight basic fibroblast growth factor with endothelium: Biological activity and intracellular fate of human recombinant Mr 24,000 bFGF",
abstract = "The single-copy gene of human basic fibroblast growth factor (bFGF) encodes four co-expressed isoforms, with an apparent molecular weight (Mr) of 24 kD, 22.5 kD, 22 kD, and 18 kD, co-translated from a single mRNA. As a tool for the study of the role exerted by the different bFGF isoforms in the biology of endothelial cells, human recombinant 24-kD bFGF was produced and purified from transformed Escherichia coli cells. To this purpose, the novel CUG start codon present in human bFGF cDNA and responsible for the synthesis of 24-kD bFGF was mutaC genized to the classic AUG start codon. Transient expression of the mutagenized cDNA in simian COS-1 cells, followed by immunolocalization and subcellular fractionation, resulted in the synthesis of high levels of 24-kD bFGF, which localizes in the cell nucleus as an intact protein. When the same 24-kD bFGF cDNA was expressed in E. coli, the recombinant protein was purified to homogeneity by heparin-Sepharose and ion-exchange chromatography. Recombinant 24-kD bFGF was similar to recombinant 18-kD bFGF in receptor-binding activity and in inducing cell proliferation, plasminogen activator production, and chemotactic movement in cultured endothelial cells. In agreement with the in vitro observations, 24-kD bFGF and 18-kD bFGF exerted a similar angiogenic response when assayed in vivo in the rabbit cornea. Experiments performed with the radiolabeled molecule demonstrated that 24-kD bFGF has an intrinsic ability to bind to high-affinity receptors when added to endothelial GM 7373 cell cultures. Receptor-bound 24-kD bFGF is internalized within the cell and associates with the nucleus with kinetics similar to 18-kD bFGF. Internalized 24-kD bFGF is first processed to the 18-kD form via a chloroquine-insensitive pathway and then to smaller fragments into the lysosomal compartment. At variance with the data obtained in transfected COS-1 cells, only limited amounts of exogenous internalized 24-kD bFGF associates with the nucleus in the intact form, mostly of the nuclear-bound molecule being represented by the processed 18-kD protein and by smaller degradation products. In conclusion, human recombinant 24-kD bFGF exerts a biological response in endothelial cells similar to 18-kD bFGF both in vitro and in vivo. Our data point to a different intracellular behavior of the high-molecular-weight bFGF isoform when added exogenously to cultured cells or when produced endogenously in transfected cells.",
author = "A. Gualandris and C. Urbinati and M. Rusnati and M. Ziche and M. Presta",
year = "1994",
month = "10",
language = "English",
volume = "161",
pages = "149--159",
journal = "Journal of cellular and comparative physiology",
issn = "0021-9541",
publisher = "Wiley-Liss Inc.",
number = "1",

}

TY - JOUR

T1 - Interaction of high-molecular-weight basic fibroblast growth factor with endothelium

T2 - Biological activity and intracellular fate of human recombinant Mr 24,000 bFGF

AU - Gualandris, A.

AU - Urbinati, C.

AU - Rusnati, M.

AU - Ziche, M.

AU - Presta, M.

PY - 1994/10

Y1 - 1994/10

N2 - The single-copy gene of human basic fibroblast growth factor (bFGF) encodes four co-expressed isoforms, with an apparent molecular weight (Mr) of 24 kD, 22.5 kD, 22 kD, and 18 kD, co-translated from a single mRNA. As a tool for the study of the role exerted by the different bFGF isoforms in the biology of endothelial cells, human recombinant 24-kD bFGF was produced and purified from transformed Escherichia coli cells. To this purpose, the novel CUG start codon present in human bFGF cDNA and responsible for the synthesis of 24-kD bFGF was mutaC genized to the classic AUG start codon. Transient expression of the mutagenized cDNA in simian COS-1 cells, followed by immunolocalization and subcellular fractionation, resulted in the synthesis of high levels of 24-kD bFGF, which localizes in the cell nucleus as an intact protein. When the same 24-kD bFGF cDNA was expressed in E. coli, the recombinant protein was purified to homogeneity by heparin-Sepharose and ion-exchange chromatography. Recombinant 24-kD bFGF was similar to recombinant 18-kD bFGF in receptor-binding activity and in inducing cell proliferation, plasminogen activator production, and chemotactic movement in cultured endothelial cells. In agreement with the in vitro observations, 24-kD bFGF and 18-kD bFGF exerted a similar angiogenic response when assayed in vivo in the rabbit cornea. Experiments performed with the radiolabeled molecule demonstrated that 24-kD bFGF has an intrinsic ability to bind to high-affinity receptors when added to endothelial GM 7373 cell cultures. Receptor-bound 24-kD bFGF is internalized within the cell and associates with the nucleus with kinetics similar to 18-kD bFGF. Internalized 24-kD bFGF is first processed to the 18-kD form via a chloroquine-insensitive pathway and then to smaller fragments into the lysosomal compartment. At variance with the data obtained in transfected COS-1 cells, only limited amounts of exogenous internalized 24-kD bFGF associates with the nucleus in the intact form, mostly of the nuclear-bound molecule being represented by the processed 18-kD protein and by smaller degradation products. In conclusion, human recombinant 24-kD bFGF exerts a biological response in endothelial cells similar to 18-kD bFGF both in vitro and in vivo. Our data point to a different intracellular behavior of the high-molecular-weight bFGF isoform when added exogenously to cultured cells or when produced endogenously in transfected cells.

AB - The single-copy gene of human basic fibroblast growth factor (bFGF) encodes four co-expressed isoforms, with an apparent molecular weight (Mr) of 24 kD, 22.5 kD, 22 kD, and 18 kD, co-translated from a single mRNA. As a tool for the study of the role exerted by the different bFGF isoforms in the biology of endothelial cells, human recombinant 24-kD bFGF was produced and purified from transformed Escherichia coli cells. To this purpose, the novel CUG start codon present in human bFGF cDNA and responsible for the synthesis of 24-kD bFGF was mutaC genized to the classic AUG start codon. Transient expression of the mutagenized cDNA in simian COS-1 cells, followed by immunolocalization and subcellular fractionation, resulted in the synthesis of high levels of 24-kD bFGF, which localizes in the cell nucleus as an intact protein. When the same 24-kD bFGF cDNA was expressed in E. coli, the recombinant protein was purified to homogeneity by heparin-Sepharose and ion-exchange chromatography. Recombinant 24-kD bFGF was similar to recombinant 18-kD bFGF in receptor-binding activity and in inducing cell proliferation, plasminogen activator production, and chemotactic movement in cultured endothelial cells. In agreement with the in vitro observations, 24-kD bFGF and 18-kD bFGF exerted a similar angiogenic response when assayed in vivo in the rabbit cornea. Experiments performed with the radiolabeled molecule demonstrated that 24-kD bFGF has an intrinsic ability to bind to high-affinity receptors when added to endothelial GM 7373 cell cultures. Receptor-bound 24-kD bFGF is internalized within the cell and associates with the nucleus with kinetics similar to 18-kD bFGF. Internalized 24-kD bFGF is first processed to the 18-kD form via a chloroquine-insensitive pathway and then to smaller fragments into the lysosomal compartment. At variance with the data obtained in transfected COS-1 cells, only limited amounts of exogenous internalized 24-kD bFGF associates with the nucleus in the intact form, mostly of the nuclear-bound molecule being represented by the processed 18-kD protein and by smaller degradation products. In conclusion, human recombinant 24-kD bFGF exerts a biological response in endothelial cells similar to 18-kD bFGF both in vitro and in vivo. Our data point to a different intracellular behavior of the high-molecular-weight bFGF isoform when added exogenously to cultured cells or when produced endogenously in transfected cells.

UR - http://www.scopus.com/inward/record.url?scp=0027987884&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027987884&partnerID=8YFLogxK

M3 - Article

C2 - 7929600

AN - SCOPUS:0027987884

VL - 161

SP - 149

EP - 159

JO - Journal of cellular and comparative physiology

JF - Journal of cellular and comparative physiology

SN - 0021-9541

IS - 1

ER -