Insulin-like growth factor-binding protein-3 (IGFBP-3) concentration in rat Sertoli cell-conditioned medium is regulated by a pathway involving association of IGFBP-3 with cell surface proteoglycans.

Endocrinology ◽  
1994 ◽  
Vol 135 (1) ◽  
pp. 359-364 ◽  
Author(s):  
E P Smith ◽  
L Lu ◽  
S D Chernausek ◽  
D J Klein
Keyword(s):  
Growth Factor ◽  
Cell Surface ◽  
Conditioned Medium ◽  
Sertoli Cell ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Cell Conditioned Medium ◽  
Igfbp 3

The ovine pancreatic protein which binds insulin-like growth factor binding protein-3 is procarboxypeptidase A

1996 ◽  
Vol 150 (1) ◽  
pp. 51-56 ◽  
Author(s):  
P J Fowke ◽  
S C Hodgkinson
Keyword(s):  
Growth Factor ◽  
Cell Surface ◽  
Binding Protein ◽  
Binding Activity ◽  
Insulin Like Growth Factor ◽  
Surface Binding ◽  
Factor Binding ◽  
Amino Terminal ◽  
Igf I ◽  
Igfbp 3

Abstract Insulin-like growth factor binding protein-3 (IGFBP-3) is known to modulate the actions of insulin-like growth factors (IGF)-I and -II at the level of the cell. Proposed mechanisms include association of IGFBP-3 with cell surface proteoglycan, with cell surface binding proteins, proteolysis and/or internalization of IGFBP-3. In previous studies we have characterized a protein of 40 kDa in extracts of ovine pancreas and muscle which binds IGFBP-3 on ligand blot analyses. This paper reports the identity of the pancreatic species as procarboxypeptidase A (peptidyl-l-amino acid hydrolase, E.C. 3.4.17.1; proCPA). Identity was established by amino terminal sequence analysis, binding studies with pure bovine carboxypeptidase A (CPA) and observations that the binding activity was present in pancreatic secretions consistent with the role of proCPA as a secretory zymogen. The binding activity was inhibited by unlabelled IGFBP-3 at high doses (10 μg/ml) and reduced but not abolished by preincubation of 125I-IGFBP-3 with excess IGF-I. Digestion of 125I-IGFBP-3 with mature CPA produced a 26 kDa product. Modification of IGFBP-3 by CPA or binding to proCPA may provide a mechanism for modulation of IGFBP activity and hence IGF action. Journal of Endocrinology (1996) 150, 51–56

Insulin-like growth factor-binding protein-3 expression and secretion by cultures of human prostate epithelial cells and stromal fibroblasts

1994 ◽  
Vol 141 (3) ◽  
pp. 535-540 ◽  
Author(s):  
R S Birnbaum ◽  
J L Ware ◽  
S R Plymate
Keyword(s):  
Growth Factor ◽  
Epithelial Cells ◽  
Conditioned Medium ◽  
Binding Protein ◽  
Human Prostate ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Cell Extracts ◽  
Prostate Epithelial Cells ◽  
Igfbp 3

Abstract Prostate-specific antigen (PSA) was recently shown to be an insulin-like growth factor-binding protein (IGFBP)-3 protease. However, only IGFBPs-2 and -4 have been identified in conditioned medium of prostate epithelial cells. Using cultures of human prostate epithelial and stromal fibroblastic cells, we examined conditioned medium and cell extracts for evidence of IGFBP-3 expression and secretion. Western ligand blotting of conditioned medium from epithelial or stromal cultures revealed the presence of IGFBPs in the molecular weight range 36–48 kDa, suggestive of IGFBP-3. Western immunoblots of these media confirmed the presence of IGFBP-3. Northern analyses of extracts of both stromal and epithelial cells showed a 2·5 kb band, the size of IGFBP-3 mRNA. We conclude that prostate cells express IGFBP-3 and that local proteolysis by PSA could modify this binding protein's actions in the prostate. Journal of Endocrinology (1994) 141, 535–540

scholarly journals Characterisation of recombinant glycosylation variants of insulin-like growth factor binding protein-3

1999 ◽  
Vol 160 (3) ◽  
pp. 379-387 ◽  
Author(s):  
SM Firth ◽  
RC Baxter
Keyword(s):  
Growth Factor ◽  
Cell Surface ◽  
Binding Protein ◽  
Biological Activities ◽  
Chinese Hamster Ovary Cells ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Glycosylation Sites ◽  
Igf I ◽  
Igfbp 3

There are three potential N-glycosylation sites in the non-conserved central region of the insulin-like growth factor binding protein-3 (IGFBP-3) sequence (N89AS, N109AS, N172FS). IGFBP-3 exists as two glycoforms which reduce to a single form on enzymatic deglycosylation. To determine the functional significance of the carbohydrate chains, the N-glycosylation sites were mutated singly and in combinations by substituting Asn residues with Ala. Each recombinant glycoform was detected by radioimmunoassay, indicating that glycosylation is not essential for secretion in Chinese hamster ovary cells. Ligand blotting of the conditioned media using [125I]IGF-I indicated that all seven mutants are active. On the basis of the number and molecular masses of the bands detected for each glycoform, there is approximately 4, 4.5 and 5 kDa of carbohydrate on Asn89, Asn109 and Asn172 respectively, with variable occupancy of Asn172. Ternary complex formation by the glycovariants in the presence of ALS and excess IGF-I was not significantly different from that of fully glycosylated recombinant human (rh)IGFBP-3 [Ka (fully glycosylated)=12.5+/-4.1 l/nmol; mean Ka (all mutants)=22.1+/-3.0 l/nmol]. In contrast, Asn to Asp substitutions decreased acid-labile subunit (ALS) binding activity. Cell-surface association experiments indicate that glycosylation may influence the partitioning of IGFBP-3 between the extracellular milieu and the cell surface. Therefore, while the carbohydrate units appear to be non-essential to ALS or IGF binding, they may modulate other biological activities of IGFBP-3.

Production of insulin-like growth factor binding protein (IGFBP), IGFBP-3 protease, and expression of IGF-I receptors by cells of the sheep immune system

1995 ◽  
Vol 132 (1) ◽  
pp. 118-122 ◽  
Author(s):  
Elizabeth Tonner ◽  
James Beattie ◽  
David J Flint
Keyword(s):  
Immune System ◽  
Growth Factor ◽  
Conditioned Medium ◽  
Binding Protein ◽  
Lymphoid Cells ◽  
Scatchard Analysis ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Igf I ◽  
Igfbp 3

Tonner E, Beattie J, Flint DJ. Production of insulin-like growth factor binding protein (IGFBP), IGFBP-3 protease, and expression of IGF-I receptors by cells of the sheep immune system. Eur J Endocrinol 1995;132:118–22. ISSN 0804–4643 Single-cell suspensions of sheep thymus cells were cultured in serum-free medium with or without polyclonal activators (phytohaemagglutinin or concanavalin A) and the resultant conditioned medium was assayed for insulin-like growth factor binding protein (IGFBP) activity by binding of [125I]IGF-I, using charcoal to separate free from bound. All cultures produced IGFBP but mitogen stimulation significantly increased IGFBP concentrations, indicating production by lymphoid cells. Conditioned medium also degraded recombinant human [125I]IGFBP-3, suggesting IGFBP-3 protease production within the thymus. This degradation was inhibited by several protease inhibitors (phenylmethylsulphonyl fluoride, aprotinin, N-α-p-tosyl-l-lysine chloromethyl ketone), suggesting the presence of a serine protease. Cell surface [125I]IGF-I binding was demonstrated on cells from thymus, mesenteric lymph node, peripheral blood mononuclear cells and platelets. The [125I]IGF-I binding to platelets could be inhibited by unlabelled peptides, with relative potencies IGF-I > IGF-II ≫ insulin. Scatchard analysis of IGF-I competitive binding revealed a Kd of 266 pmol/l and approximately 40 receptor sites per cell. The high-affinity binding of IGF-I and competition by insulin suggested that the [125I]IGF-I binding was to an IGF-I receptor rather than to a membrane-associated IGFBP, to which insulin does not bind. These data provide further support for the role of the IGF-IGFBP axis in the immune system, particularly in relation to the thymus. Elizabeth Tonner, Hannah Research Institute, Ayr, UK

scholarly journals Histone deacetylase inhibitors enhance the apoptotic activity of insulin-like growth factor binding protein-3 by blocking PKC-induced IGFBP-3 degradation

2012 ◽  
Vol 131 (10) ◽  
pp. 2253-2263 ◽  
Author(s):  
Seung Hyun Oh ◽  
Young Mi Whang ◽  
Hye-Young Min ◽  
Seung Ho Han ◽  
Ju-Hee Kang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Histone Deacetylase ◽  
Histone Deacetylase Inhibitors ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Apoptotic Activity ◽  
Igfbp 3

Insulin-like growth factor binding protein (IGFBP)-3 and IGFBP-5 mediate TGF-β- and myostatin-induced suppression of proliferation in porcine embryonic myogenic cell cultures

2005 ◽  
Vol 311 (1) ◽  
pp. 167-176 ◽  
Author(s):  
E. Kamanga-Sollo ◽  
M.S. Pampusch ◽  
M.E. White ◽  
M.R. Hathaway ◽  
W.R. Dayton
Keyword(s):  
Growth Factor ◽  
Cell Cultures ◽  
Binding Protein ◽  
Myogenic Cell ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Igfbp 3

scholarly journals Correlation between the Expression Reduction of Insulin-like Growth Factor Binding Protein (IGFBP)-3 and PTEN and the Clinicopathological Parameters in Breast Cancer

2010 ◽  
Vol 79 (2) ◽  
pp. 79
Author(s):  
Sung Hoo Jung ◽  
Hyun Jo Youn ◽  
Min Sun Kim ◽  
Sun-Young Kim ◽  
Pyoung Han Hwang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Binding Protein ◽  
Clinicopathological Parameters ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Igfbp 3

scholarly journals Malnutrition in children associated with low insulin-like growth factor binding protein-3 (IGFBP-3) levels

2021 ◽  
Vol 35 ◽  
pp. S275-S277
Author(s):  
Dwi Ayu Rahmawati ◽  
Aminuddin Aminuddin ◽  
Firdaus Hamid ◽  
Prihantono Prihantono ◽  
Burhanuddin Bahar ◽  
...  
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Igfbp 3
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