Receptors for insulin-like growth factor II in the rat uterus: characterization and variation throughout the estrus cycle

1991 ◽  
Vol 124 (4) ◽  
pp. 434-441 ◽  
Author(s):  
Yallampalli Chandrasekhar ◽  
Satya Narayan ◽  
Pomila Singh ◽  
Manubai Nagamani
Keyword(s):  
Growth Factor ◽  
Binding Sites ◽  
Binding Capacity ◽  
Specific Binding ◽  
Cross Linking ◽  
Dependent Manner ◽  
Insulin Like Growth Factor ◽  
Estrus Cycle ◽  
Rat Uterus ◽  
Factor Ii

Abstract This study was undertaken to identify uterine insulin-like growth factor II receptors and examine the regulation of these receptor levels throughout the estrus cycle. We have demonstrated IGF-II receptors in crude uterine membranes by binding and cross-linking experiments. IGF-II binding to the rat uterine membranes displayed time and temperature dependence and maximum binding was achieved by 2 h at 22°C. Uterine IGF-II binding sites were specific for binding IGF-II peptide and demonstrated negligible binding affinity for IGF-I and no affinity for insulin. The specific anti-IGF-II receptor antibody, R-II-PAB1, blocked the specific [125I]IGF-II binding to uterine membranes in a dose-dependent manner. The characteristics of uterine IGF-II receptor are similar to those reported for other tissues, with a single class of high-affinity binding sites with an apparent dissociation constant of 1.2±0.5 nmol/l and βmax of 2.65±0.41 pmol/mg protein. Affinity cross-linking experiments indicated that the specific binding of [125I]IGF-II in the uterus is associated with a single band of protein with a mol wt of 250 kD. In mature cycling rats, the proestrus uterus had the lowest level of [125I]IGF-II binding per mg membrane protein, without changes in receptor affinity. However, because of greater yield of protein from proestrus uteri, the total [125I]IGF-II binding capacity of the uterus was similar to the other stages of the estrus cycle. These studies demonstrate the presence of authentic IGF-II receptors in the rat uterus and illustrate variations in the concentration of these receptors in the uterus throughout the estrus cycle.

Receptors for insulin-like growth factor-II in the growing tip of the deer antler

1993 ◽  
Vol 138 (2) ◽  
pp. 233-NP ◽  
Author(s):  
J. L. Elliott ◽  
J. M. Oldham ◽  
G. R. Ambler ◽  
P. C. Molan ◽  
G. S. G. Spencer ◽  
...  
Keyword(s):  
Growth Factor ◽  
Specific Binding ◽  
Cross Linking ◽  
Insulin Like Growth Factor ◽  
Deer Antler ◽  
Reducing Conditions ◽  
Factor Ii ◽  
Igf I ◽  
Igf Receptor

ABSTRACT Insulin-like growth factor-II (IGF-II) binding in the growing tip of the deer antler was examined using autoradiographical studies, radioreceptor assays and affinity cross-linking studies. Antler tips from red deer stags were removed 60 days after the commencement of growth, and cryogenically cut into sections. Sections were incubated with radiolabelled IGF-II, with or without an excess of competing unlabelled IGF-II and analysed autoradiographically. Radiolabelled IGF-II showed high specific binding in the reserve mesenchyme and perichondrium zones, which are tissues undergoing rapid differentiation and cell division in the antler. Binding to all other structural zones was low and significantly (P<0·001) less than binding to the reserve mesenchyme/perichondrium zones. Radioreceptor assays on antler microsomal membrane preparations revealed that the IGF-II binding was to a relatively homogeneous receptor population (Kd= 1·3 × 10−10 mol/l) with characteristics that were not entirely consistent with those normally attributed to the type 2 IGF receptor. Tracer binding was partly displaceable by IGF-I and insulin at concentrations above 10 nmol/l. However, affinity cross-linking studies revealed a single band migrating at 220 kDa under non-reducing conditions, indicative of the type 2 IGF receptor. These results indicate that, in antler tip tissues, IGF-II binds to sites which have different binding patterns and properties from receptors binding IGF-I. This may have functional significance as it appears that, whilst IGF-I has a role in matrix development of cartilage, IGF-II may have a role in the most rapidly differentiating and proliferating tissues of the antler. Journal of Endocrinology (1993) 138, 233–241

Mannose 6-phosphate/insulin-like growth factor II receptor: Distinct binding sites for mannose 6-phosphate and insulin-like growth factor II

1988 ◽  
Vol 150 (3) ◽  
pp. 1287-1293 ◽  
Author(s):  
Thomas Braulke ◽  
Christa Causin ◽  
Abdul Waheed ◽  
Ulrich Junghans ◽  
Andrej Hasilik ◽  
...  
Keyword(s):  
Growth Factor ◽  
Binding Sites ◽  
Insulin Like Growth Factor ◽  
Factor Ii ◽  
Mannose 6 Phosphate

Evidence for insulin-like growth factor-II binding sites in smooth muscle of stem villi vessels of human term placenta

Placenta ◽  
1993 ◽  
Vol 14 (4) ◽  
pp. A61
Author(s):  
R. Rebourcet ◽  
J. Willeput ◽  
F. De Ceuninck ◽  
F. Mondon ◽  
F. Ferré
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Binding Sites ◽  
Insulin Like Growth Factor ◽  
Human Term Placenta ◽  
Term Placenta ◽  
Factor Ii ◽  
Stem Villi

[Leu27] INSULIN-LIKE GROWTH FACTOR II IS HIGHLY SELECTIVE FOR THE TYPE-II IGF RECEPTOR IN BINDING, CROSS-LINKING AND THYMIDINE INCORPORATION EXPERIMENTS

Endocrinology ◽  
1991 ◽  
Vol 128 (2) ◽  
pp. 1201-1203 ◽  
Author(s):  
Margot W Beukers ◽  
Youngman Oh ◽  
Heping Zhang ◽  
Nicholas Ling ◽  
Ron G Rosenfeld
Keyword(s):  
Growth Factor ◽  
Thymidine Incorporation ◽  
Cross Linking ◽  
Insulin Like Growth Factor ◽  
Type Ii ◽  
Factor Ii ◽  
Igf Receptor

Processing of the insulin-like growth factor-II–mannose 6-phosphate receptor in isolated liver subcellular fractions

2001 ◽  
Vol 79 (4) ◽  
pp. 469-477
Author(s):  
Khadija Tahiri ◽  
Laurence Cam ◽  
Bernard Desbuquois ◽  
Geneviève Chauvet
Keyword(s):  
Plasma Membrane ◽  
Growth Factor ◽  
Polyacrylamide Gel Electrophoresis ◽  
Subcellular Fractions ◽  
Soluble Form ◽  
Dependent Manner ◽  
Insulin Like Growth Factor ◽  
Factor Ii ◽  
Mannose 6 Phosphate ◽  
Isolated Liver

A truncated, soluble form of the insulin-like growth factor-II–mannose 6-phosphate (IGF-II–M6P) receptor has been identified in serum and shown to be released from cultured tissues and cells, liver being the main contributor to serum receptor in adult rats. In the present study, the processing of the IGF-II–M6P receptor has been characterized in isolated liver subcellular fractions using ligand binding, affinity crosslinking, and Western immunoblotting techniques. The receptor in plasma membrane fractions differed from that in Golgi-endosomal fractions by: (i) a lower molecular size upon reducing polyacrylamide gel electrophoresis (245 vs. 255 kDa); (ii) a less tight membrane association as judged upon extractibility by NaCl; and (iii) the inability to recognize antibody anti-22C, directed against the cytoplasmic domain of the receptor. Incubation of cell fractions at 30°C led to a pH- and time-dependent release of the receptor into the medium. The pH optimum for release was 5.5 in the Golgi-endosomal fraction and 7.5 in plasma membrane fractions; at this pH, approximately 2% and 20%–30% of total receptors were released per hour, respectively. Receptor release was inhibited in a dose-dependent manner by aprotinin, benzamidine, and leupeptin in the Golgi-endosomal fraction, and by 1,10 phenanthroline in plasma membrane fractions, although high concentrations were required for inhibition. The receptor released from Golgi-endosomes showed a 5–10 kDa reduction in size and a loss of ability to recognize antibody anti-22C, but that released from plasma membranes showed little or no changes in size. We conclude that soluble, carboxy-terminally truncated forms of the IGF-II–M6P receptor are generated from the intact receptor in isolated Golgi-endosomal and plasma membrane fractions. However, receptor processing in these fractions exhibits different properties, suggesting the involvement of different proteases.Key words: insulin-like growth factor-II–mannose 6-phosphate (IGF-II–M6P) receptor, liver, plasma membrane, Golgi apparatus, endosomes.

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