Truncated Forms of the Insulin-like Growth Factor II (IGF-II)/ Mannose 6-Phosphate Receptor Encompassing the IGF-II Binding Site

Characterization of a Point Mutation That Abolishes IGF-II Binding

Farideh Garmroudi, Gayathri Devi, Dorothy H. Slentz, Beverly S. Schaffer, Richard G MacDonald

Research output: Contribution to journalArticle

52 Citations (Scopus)

Abstract

Complete understanding of the functional significance of insulin-like growth factor II (IGF-II) binding by the IGF-II/mannose-6-phosphate (Man-6-P) receptor requires mapping and ultimately mutational analysis of the receptor's IGF-II binding domain. Recent advances have localized the IGF-II binding site to extracytoplasmic repeats 10-11. To improve resolution of the binding site map, a nested set of epitope-tagged, truncated forms of the human IGF-II/Man-6-P receptor were transiently expressed in COS-7 cells. The IGF-II binding properties of truncated receptors immunoprecipitated from cell lysates and conditioned media were determined by affinity cross-linking. From the largest truncated receptor, encompassing extracytoplasmic repeats 8-11 (Mr 68 K), through the smallest, comprised primarily of repeat 11 (Mr 23 K), all were able to bind and cross-link to IGF-II. As a group, the truncated receptors had similar affinities for IGF-II, but with relative binding affinities 5-to 10-fold lower than those of full-length receptors. A point mutation substituting threonine for isoleucine at residue 1572, located in the NH2-terminal half of repeat 11, completely abolished IGF-II binding. We conclude that repeat 11 of the IGF-II/Man-6-P receptor's extracytoplasmic domain contains the minimal elements required for binding and cross-linking to IGF-II, and that Me1572 and other residues within the NH2-terminal half of repeat 11 are particularly important for IGF-II interaction.

Original languageEnglish (US)
Pages (from-to)642-651
Number of pages10
JournalMolecular Endocrinology
Volume10
Issue number6
StatePublished - Dec 1 1996

Fingerprint

IGF Type 2 Receptor
Insulin-Like Growth Factor II
Point Mutation
Binding Sites
Terminal Repeat Sequences
Isoleucine
COS Cells
Threonine
Conditioned Culture Medium
Epitopes

ASJC Scopus subject areas

  • Molecular Biology
  • Endocrinology

Cite this

Truncated Forms of the Insulin-like Growth Factor II (IGF-II)/ Mannose 6-Phosphate Receptor Encompassing the IGF-II Binding Site : Characterization of a Point Mutation That Abolishes IGF-II Binding. / Garmroudi, Farideh; Devi, Gayathri; Slentz, Dorothy H.; Schaffer, Beverly S.; MacDonald, Richard G.

In: Molecular Endocrinology, Vol. 10, No. 6, 01.12.1996, p. 642-651.

Research output: Contribution to journalArticle

@article{4e1583665ffe4851bb3251a0c7438afe,
title = "Truncated Forms of the Insulin-like Growth Factor II (IGF-II)/ Mannose 6-Phosphate Receptor Encompassing the IGF-II Binding Site: Characterization of a Point Mutation That Abolishes IGF-II Binding",
abstract = "Complete understanding of the functional significance of insulin-like growth factor II (IGF-II) binding by the IGF-II/mannose-6-phosphate (Man-6-P) receptor requires mapping and ultimately mutational analysis of the receptor's IGF-II binding domain. Recent advances have localized the IGF-II binding site to extracytoplasmic repeats 10-11. To improve resolution of the binding site map, a nested set of epitope-tagged, truncated forms of the human IGF-II/Man-6-P receptor were transiently expressed in COS-7 cells. The IGF-II binding properties of truncated receptors immunoprecipitated from cell lysates and conditioned media were determined by affinity cross-linking. From the largest truncated receptor, encompassing extracytoplasmic repeats 8-11 (Mr 68 K), through the smallest, comprised primarily of repeat 11 (Mr 23 K), all were able to bind and cross-link to IGF-II. As a group, the truncated receptors had similar affinities for IGF-II, but with relative binding affinities 5-to 10-fold lower than those of full-length receptors. A point mutation substituting threonine for isoleucine at residue 1572, located in the NH2-terminal half of repeat 11, completely abolished IGF-II binding. We conclude that repeat 11 of the IGF-II/Man-6-P receptor's extracytoplasmic domain contains the minimal elements required for binding and cross-linking to IGF-II, and that Me1572 and other residues within the NH2-terminal half of repeat 11 are particularly important for IGF-II interaction.",
author = "Farideh Garmroudi and Gayathri Devi and Slentz, {Dorothy H.} and Schaffer, {Beverly S.} and MacDonald, {Richard G}",
year = "1996",
month = "12",
day = "1",
language = "English (US)",
volume = "10",
pages = "642--651",
journal = "Molecular Endocrinology",
issn = "0888-8809",
publisher = "The Endocrine Society",
number = "6",

}

TY - JOUR

T1 - Truncated Forms of the Insulin-like Growth Factor II (IGF-II)/ Mannose 6-Phosphate Receptor Encompassing the IGF-II Binding Site

T2 - Characterization of a Point Mutation That Abolishes IGF-II Binding

AU - Garmroudi, Farideh

AU - Devi, Gayathri

AU - Slentz, Dorothy H.

AU - Schaffer, Beverly S.

AU - MacDonald, Richard G

PY - 1996/12/1

Y1 - 1996/12/1

N2 - Complete understanding of the functional significance of insulin-like growth factor II (IGF-II) binding by the IGF-II/mannose-6-phosphate (Man-6-P) receptor requires mapping and ultimately mutational analysis of the receptor's IGF-II binding domain. Recent advances have localized the IGF-II binding site to extracytoplasmic repeats 10-11. To improve resolution of the binding site map, a nested set of epitope-tagged, truncated forms of the human IGF-II/Man-6-P receptor were transiently expressed in COS-7 cells. The IGF-II binding properties of truncated receptors immunoprecipitated from cell lysates and conditioned media were determined by affinity cross-linking. From the largest truncated receptor, encompassing extracytoplasmic repeats 8-11 (Mr 68 K), through the smallest, comprised primarily of repeat 11 (Mr 23 K), all were able to bind and cross-link to IGF-II. As a group, the truncated receptors had similar affinities for IGF-II, but with relative binding affinities 5-to 10-fold lower than those of full-length receptors. A point mutation substituting threonine for isoleucine at residue 1572, located in the NH2-terminal half of repeat 11, completely abolished IGF-II binding. We conclude that repeat 11 of the IGF-II/Man-6-P receptor's extracytoplasmic domain contains the minimal elements required for binding and cross-linking to IGF-II, and that Me1572 and other residues within the NH2-terminal half of repeat 11 are particularly important for IGF-II interaction.

AB - Complete understanding of the functional significance of insulin-like growth factor II (IGF-II) binding by the IGF-II/mannose-6-phosphate (Man-6-P) receptor requires mapping and ultimately mutational analysis of the receptor's IGF-II binding domain. Recent advances have localized the IGF-II binding site to extracytoplasmic repeats 10-11. To improve resolution of the binding site map, a nested set of epitope-tagged, truncated forms of the human IGF-II/Man-6-P receptor were transiently expressed in COS-7 cells. The IGF-II binding properties of truncated receptors immunoprecipitated from cell lysates and conditioned media were determined by affinity cross-linking. From the largest truncated receptor, encompassing extracytoplasmic repeats 8-11 (Mr 68 K), through the smallest, comprised primarily of repeat 11 (Mr 23 K), all were able to bind and cross-link to IGF-II. As a group, the truncated receptors had similar affinities for IGF-II, but with relative binding affinities 5-to 10-fold lower than those of full-length receptors. A point mutation substituting threonine for isoleucine at residue 1572, located in the NH2-terminal half of repeat 11, completely abolished IGF-II binding. We conclude that repeat 11 of the IGF-II/Man-6-P receptor's extracytoplasmic domain contains the minimal elements required for binding and cross-linking to IGF-II, and that Me1572 and other residues within the NH2-terminal half of repeat 11 are particularly important for IGF-II interaction.

UR - http://www.scopus.com/inward/record.url?scp=0029969904&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029969904&partnerID=8YFLogxK

M3 - Article

VL - 10

SP - 642

EP - 651

JO - Molecular Endocrinology

JF - Molecular Endocrinology

SN - 0888-8809

IS - 6

ER -