Cell surface site for mitogenic interaction of erythropoietin receptors with the membrane glycoprotein encoded by Friend erythroleukemia virus

Frank E. Ferro, Susan L. Kozak, Maureen Hoatlin, David Kabat

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

The membrane glycoprotein (gp55) encoded by the env gene of Friend spleen focus-forming virus (SFFV) causes mitogenesis of infected erythroblasts and is inefficiently (3-5%) processed from the rough endoplasmic reticulum (RER) to plasma membranes. Recent evidence suggested that gp55 binds to erythropoietin receptors (EpoR) in the RER, and it was proposed that this intracellular interaction causes mitogenesis (Li, J.-P., D'Andrea, A. D., Lodish, H. F., and Baltimore, D. (1990) Nature 343, 762-764). Other evidence has indicated that the plasma membrane component (gp55p) can also complex with EpoR. To identify the site of functional complexes and to study the factors that control their formation, we analyzed eight SFFV env mutants that contain in-frame deletions or linker insertions. The three nonpathogenic mutants encode gp55s that fail to leave the RER, whereas the five pathogenic mutants encode glycoproteins that occur on cell surfaces. Although BaF3 hematopoietic cells are interleukin 3 (IL-3)-dependent, a cellular derivative BaF3/EpoR that contains EpoR survives and grows in either IL-3 or erythropoietin (Epo). The five pathogenic SFFV env mutants converted BaF3/EpoR but not BaF3 cells to growth factor independence, whereas the nonpathogenic mutants did not eliminate growth factor requirements of any cells. Studies using 125I-Epo and the covalent cross-linking reagent disuccinimidyl suberate provided unambiguous evidence for ternary complexes of 125I-Epo·EpoR·gp55P on surfaces of all factor-independent cells. Size of the cell surface complex was correspondingly reduced in the case of a newly isolated SFFV mutant that encodes a severely truncated (Mr ∼ 41,000) but mitogenically active env glycoprotein. Our results support the hypothesis that activation of EpoR by the SFFV env glycoprotein occurs exclusively on cell surfaces.

Original languageEnglish (US)
Pages (from-to)5741-5747
Number of pages7
JournalJournal of Biological Chemistry
Volume268
Issue number8
StatePublished - Mar 15 1993

Fingerprint

Friend murine leukemia virus
Erythropoietin Receptors
Spleen Focus-Forming Viruses
Leukemia, Erythroblastic, Acute
Membrane Glycoproteins
Viruses
Rough Endoplasmic Reticulum
env Gene Products
Interleukin-3
Cell membranes
Erythropoietin
Intercellular Signaling Peptides and Proteins
Cell Membrane
Cross-Linking Reagents
env Genes
Erythroblasts
Cell Size
Glycoproteins
Genes
Chemical activation

ASJC Scopus subject areas

  • Biochemistry

Cite this

Cell surface site for mitogenic interaction of erythropoietin receptors with the membrane glycoprotein encoded by Friend erythroleukemia virus. / Ferro, Frank E.; Kozak, Susan L.; Hoatlin, Maureen; Kabat, David.

In: Journal of Biological Chemistry, Vol. 268, No. 8, 15.03.1993, p. 5741-5747.

Research output: Contribution to journalArticle

@article{24b6177ac1ad4a74b43d209a7b9e927e,
title = "Cell surface site for mitogenic interaction of erythropoietin receptors with the membrane glycoprotein encoded by Friend erythroleukemia virus",
abstract = "The membrane glycoprotein (gp55) encoded by the env gene of Friend spleen focus-forming virus (SFFV) causes mitogenesis of infected erythroblasts and is inefficiently (3-5{\%}) processed from the rough endoplasmic reticulum (RER) to plasma membranes. Recent evidence suggested that gp55 binds to erythropoietin receptors (EpoR) in the RER, and it was proposed that this intracellular interaction causes mitogenesis (Li, J.-P., D'Andrea, A. D., Lodish, H. F., and Baltimore, D. (1990) Nature 343, 762-764). Other evidence has indicated that the plasma membrane component (gp55p) can also complex with EpoR. To identify the site of functional complexes and to study the factors that control their formation, we analyzed eight SFFV env mutants that contain in-frame deletions or linker insertions. The three nonpathogenic mutants encode gp55s that fail to leave the RER, whereas the five pathogenic mutants encode glycoproteins that occur on cell surfaces. Although BaF3 hematopoietic cells are interleukin 3 (IL-3)-dependent, a cellular derivative BaF3/EpoR that contains EpoR survives and grows in either IL-3 or erythropoietin (Epo). The five pathogenic SFFV env mutants converted BaF3/EpoR but not BaF3 cells to growth factor independence, whereas the nonpathogenic mutants did not eliminate growth factor requirements of any cells. Studies using 125I-Epo and the covalent cross-linking reagent disuccinimidyl suberate provided unambiguous evidence for ternary complexes of 125I-Epo·EpoR·gp55P on surfaces of all factor-independent cells. Size of the cell surface complex was correspondingly reduced in the case of a newly isolated SFFV mutant that encodes a severely truncated (Mr ∼ 41,000) but mitogenically active env glycoprotein. Our results support the hypothesis that activation of EpoR by the SFFV env glycoprotein occurs exclusively on cell surfaces.",
author = "Ferro, {Frank E.} and Kozak, {Susan L.} and Maureen Hoatlin and David Kabat",
year = "1993",
month = "3",
day = "15",
language = "English (US)",
volume = "268",
pages = "5741--5747",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "8",

}

TY - JOUR

T1 - Cell surface site for mitogenic interaction of erythropoietin receptors with the membrane glycoprotein encoded by Friend erythroleukemia virus

AU - Ferro, Frank E.

AU - Kozak, Susan L.

AU - Hoatlin, Maureen

AU - Kabat, David

PY - 1993/3/15

Y1 - 1993/3/15

N2 - The membrane glycoprotein (gp55) encoded by the env gene of Friend spleen focus-forming virus (SFFV) causes mitogenesis of infected erythroblasts and is inefficiently (3-5%) processed from the rough endoplasmic reticulum (RER) to plasma membranes. Recent evidence suggested that gp55 binds to erythropoietin receptors (EpoR) in the RER, and it was proposed that this intracellular interaction causes mitogenesis (Li, J.-P., D'Andrea, A. D., Lodish, H. F., and Baltimore, D. (1990) Nature 343, 762-764). Other evidence has indicated that the plasma membrane component (gp55p) can also complex with EpoR. To identify the site of functional complexes and to study the factors that control their formation, we analyzed eight SFFV env mutants that contain in-frame deletions or linker insertions. The three nonpathogenic mutants encode gp55s that fail to leave the RER, whereas the five pathogenic mutants encode glycoproteins that occur on cell surfaces. Although BaF3 hematopoietic cells are interleukin 3 (IL-3)-dependent, a cellular derivative BaF3/EpoR that contains EpoR survives and grows in either IL-3 or erythropoietin (Epo). The five pathogenic SFFV env mutants converted BaF3/EpoR but not BaF3 cells to growth factor independence, whereas the nonpathogenic mutants did not eliminate growth factor requirements of any cells. Studies using 125I-Epo and the covalent cross-linking reagent disuccinimidyl suberate provided unambiguous evidence for ternary complexes of 125I-Epo·EpoR·gp55P on surfaces of all factor-independent cells. Size of the cell surface complex was correspondingly reduced in the case of a newly isolated SFFV mutant that encodes a severely truncated (Mr ∼ 41,000) but mitogenically active env glycoprotein. Our results support the hypothesis that activation of EpoR by the SFFV env glycoprotein occurs exclusively on cell surfaces.

AB - The membrane glycoprotein (gp55) encoded by the env gene of Friend spleen focus-forming virus (SFFV) causes mitogenesis of infected erythroblasts and is inefficiently (3-5%) processed from the rough endoplasmic reticulum (RER) to plasma membranes. Recent evidence suggested that gp55 binds to erythropoietin receptors (EpoR) in the RER, and it was proposed that this intracellular interaction causes mitogenesis (Li, J.-P., D'Andrea, A. D., Lodish, H. F., and Baltimore, D. (1990) Nature 343, 762-764). Other evidence has indicated that the plasma membrane component (gp55p) can also complex with EpoR. To identify the site of functional complexes and to study the factors that control their formation, we analyzed eight SFFV env mutants that contain in-frame deletions or linker insertions. The three nonpathogenic mutants encode gp55s that fail to leave the RER, whereas the five pathogenic mutants encode glycoproteins that occur on cell surfaces. Although BaF3 hematopoietic cells are interleukin 3 (IL-3)-dependent, a cellular derivative BaF3/EpoR that contains EpoR survives and grows in either IL-3 or erythropoietin (Epo). The five pathogenic SFFV env mutants converted BaF3/EpoR but not BaF3 cells to growth factor independence, whereas the nonpathogenic mutants did not eliminate growth factor requirements of any cells. Studies using 125I-Epo and the covalent cross-linking reagent disuccinimidyl suberate provided unambiguous evidence for ternary complexes of 125I-Epo·EpoR·gp55P on surfaces of all factor-independent cells. Size of the cell surface complex was correspondingly reduced in the case of a newly isolated SFFV mutant that encodes a severely truncated (Mr ∼ 41,000) but mitogenically active env glycoprotein. Our results support the hypothesis that activation of EpoR by the SFFV env glycoprotein occurs exclusively on cell surfaces.

UR - http://www.scopus.com/inward/record.url?scp=0027481011&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027481011&partnerID=8YFLogxK

M3 - Article

C2 - 8449938

AN - SCOPUS:0027481011

VL - 268

SP - 5741

EP - 5747

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 8

ER -