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. 1995 Dec;69(12):7606–7611. doi: 10.1128/jvi.69.12.7606-7611.1995

Both the changes of six amino acids and the C-terminal truncation caused by a one-base insertion in the defective env gene of Friend spleen focus-forming virus significantly affect the pathogenic activity of the encoded leukemogenic membrane glycoprotein (gp55).

N Watanabe 1, T Yugawa 1, Y Ikawa 1, H Amanuma 1
PMCID: PMC189700  PMID: 7494268

Abstract

Friend spleen focus-forming virus (F-SFFV) causes acute erythroleukemia in mice and encodes in its defective env gene an Env-like membrane glycoprotein (gp55). The F-SFFV env gene has three characteristic structures compared with that of ecotropic murine leukemia viruses (MuLVs): substitution by the polytropic MuLV env sequence, a 585-bp deletion, and a 1-bp insertion. All of these characteristic structures are essential for the leukemogenic potential of gp55 of polycythemia-inducing isolates of F-SFFV (F-SFFVp). The 1-bp insertion causes changes of six amino acids and truncation by 34 amino acids at the C terminus. In this study, we constructed 12 mutant F-SFFV genomes starting from the wild-type F-SFFVp and examined the effect of the C-terminal truncation and the six altered amino acids on the pathogenic activity of gp55. The results indicated that at least 18 to 24 amino acids must be deleted from the C terminus for the env product to be pathogenically active. We also found that the six altered amino acids contributed significantly to the pathogenic activity of gp55. Analyses of the cellular processing of these mutant gp55s supported a correlation between the pathogenic activity of gp55 and its efficiency in overall cellular processing.

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Selected References

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  1. Amanuma H., Katori A., Obata M., Sagata N., Ikawa Y. Complete nucleotide sequence of the gene for the specific glycoprotein (gp55) of Friend spleen focus-forming virus. Proc Natl Acad Sci U S A. 1983 Jul;80(13):3913–3917. doi: 10.1073/pnas.80.13.3913. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Amanuma H., Watanabe N., Nishi M., Ikawa Y. Requirement of the single base insertion at the 3' end of the env-related gene of Friend spleen focus-forming virus for pathogenic activity and its effect on localization of the glycoprotein product (gp55). J Virol. 1989 Nov;63(11):4824–4833. doi: 10.1128/jvi.63.11.4824-4833.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Ben-David Y., Bernstein A. Friend virus-induced erythroleukemia and the multistage nature of cancer. Cell. 1991 Sep 6;66(5):831–834. doi: 10.1016/0092-8674(91)90428-2. [DOI] [PubMed] [Google Scholar]
  4. Clark S. P., Mak T. W. Complete nucleotide sequence of an infectious clone of Friend spleen focus-forming provirus: gp55 is an envelope fusion glycoprotein. Proc Natl Acad Sci U S A. 1983 Aug;80(16):5037–5041. doi: 10.1073/pnas.80.16.5037. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. D'Andrea A. D., Lodish H. F., Wong G. G. Expression cloning of the murine erythropoietin receptor. Cell. 1989 Apr 21;57(2):277–285. doi: 10.1016/0092-8674(89)90965-3. [DOI] [PubMed] [Google Scholar]
  6. Gliniak B. C., Kabat D. Leukemogenic membrane glycoprotein encoded by Friend spleen focus-forming virus: transport to cell surfaces and shedding are controlled by disulfide-bonded dimerization and by cleavage of a hydrophobic membrane anchor. J Virol. 1989 Sep;63(9):3561–3568. doi: 10.1128/jvi.63.9.3561-3568.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Gliniak B. C., Kozak S. L., Jones R. T., Kabat D. Disulfide bonding controls the processing of retroviral envelope glycoproteins. J Biol Chem. 1991 Dec 5;266(34):22991–22997. [PubMed] [Google Scholar]
  8. Kabat D. Molecular biology of Friend viral erythroleukemia. Curr Top Microbiol Immunol. 1989;148:1–42. doi: 10.1007/978-3-642-74700-7_1. [DOI] [PubMed] [Google Scholar]
  9. Kishi A., Chiba T., Sugiyama M., Machide M., Nagata Y., Amanuma H., Taira H., Katsumata T., Todokoro K. Erythropoietin receptor binds to Friend virus gp55 through other membrane components. Biochem Biophys Res Commun. 1993 May 14;192(3):1131–1138. doi: 10.1006/bbrc.1993.1534. [DOI] [PubMed] [Google Scholar]
  10. Kunkel T. A., Roberts J. D., Zakour R. A. Rapid and efficient site-specific mutagenesis without phenotypic selection. Methods Enzymol. 1987;154:367–382. doi: 10.1016/0076-6879(87)54085-x. [DOI] [PubMed] [Google Scholar]
  11. Li J. P., Bestwick R. K., Spiro C., Kabat D. The membrane glycoprotein of Friend spleen focus-forming virus: evidence that the cell surface component is required for pathogenesis and that it binds to a receptor. J Virol. 1987 Sep;61(9):2782–2792. doi: 10.1128/jvi.61.9.2782-2792.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Li J. P., D'Andrea A. D., Lodish H. F., Baltimore D. Activation of cell growth by binding of Friend spleen focus-forming virus gp55 glycoprotein to the erythropoietin receptor. Nature. 1990 Feb 22;343(6260):762–764. doi: 10.1038/343762a0. [DOI] [PubMed] [Google Scholar]
  13. Obata M., Amanuma H., Harada Y., Sagata N., Ikawa Y. env-Related leukemogenic genes (gp55 genes) of two closely related polycythemic strains of Friend spleen focus-forming virus possess different recombination points with an endogenous mink cell focus-forming virus env gene. Virology. 1984 Jul 30;136(2):435–438. doi: 10.1016/0042-6822(84)90179-x. [DOI] [PubMed] [Google Scholar]
  14. Oliff A. I., Hager G. L., Chang E. H., Scolnick E. M., Chan H. W., Lowy D. R. Transfection of molecularly cloned Friend murine leukemia virus DNA yields a highly leukemogenic helper-independent type C virus. J Virol. 1980 Jan;33(1):475–486. doi: 10.1128/jvi.33.1.475-486.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Pinter A., Honnen W. J. Biochemical characterization of cell-associated and extracellular products of the Friend spleen focus-forming virus env gene. Virology. 1989 Nov;173(1):136–143. doi: 10.1016/0042-6822(89)90229-8. [DOI] [PubMed] [Google Scholar]
  16. Pinter A., Honnen W. J. The mature form of the Friend spleen focus-forming virus envelope protein, gp65, is efficiently secreted from cells. Virology. 1985 Jun;143(2):646–650. doi: 10.1016/0042-6822(85)90406-4. [DOI] [PubMed] [Google Scholar]
  17. Ruscetti S. K., Linemeyer D., Feild J., Troxler D., Scolnick E. M. Characterization of a protein found in cells infected with the spleen focus-forming virus that shares immunological cross-reactivity with the gp70 found in mink cell focus-inducing virus particles. J Virol. 1979 Jun;30(3):787–798. doi: 10.1128/jvi.30.3.787-798.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Ruscetti S., Wolff L. Spleen focus-forming virus: relationship of an altered envelope gene to the development of a rapid erythroleukemia. Curr Top Microbiol Immunol. 1984;112:21–44. doi: 10.1007/978-3-642-69677-0_2. [DOI] [PubMed] [Google Scholar]
  19. Ruta M., Clarke S., Boswell B., Kabat D. Heterogeneous metabolism and subcellular localization of a potentially leukemogenic membrane glycoprotein encoded by Friend erythroleukemia virus. Isolation of viral and cellular processing mutants. J Biol Chem. 1982 Jan 10;257(1):126–134. [PubMed] [Google Scholar]
  20. Southern P. J., Berg P. Transformation of mammalian cells to antibiotic resistance with a bacterial gene under control of the SV40 early region promoter. J Mol Appl Genet. 1982;1(4):327–341. [PubMed] [Google Scholar]
  21. Srinivas R. V., Tucker S. P., Kilpatrick D. R., Compans R. W. A 585-bp deletion found in the spleen focus-forming virus (SFFV) env gene is responsible for the defective intracellular transport of SFFV gp52. Virology. 1992 May;188(1):181–192. doi: 10.1016/0042-6822(92)90748-e. [DOI] [PubMed] [Google Scholar]
  22. Wang Y., Kayman S. C., Li J. P., Pinter A. Erythropoietin receptor (EpoR)-dependent mitogenicity of spleen focus-forming virus correlates with viral pathogenicity and processing of env protein but not with formation of gp52-EpoR complexes in the endoplasmic reticulum. J Virol. 1993 Mar;67(3):1322–1327. doi: 10.1128/jvi.67.3.1322-1327.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Watanabe N., Nishi M., Ikawa Y., Amanuma H. A deletion in the Friend spleen focus-forming virus env gene is necessary for its product (gp55) to be leukemogenic. J Virol. 1990 Jun;64(6):2678–2686. doi: 10.1128/jvi.64.6.2678-2686.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Watanabe N., Nishi M., Ikawa Y., Amanuma H. Conversion of Friend mink cell focus-forming virus to Friend spleen focus-forming virus by modification of the 3' half of the env gene. J Virol. 1991 Jan;65(1):132–137. doi: 10.1128/jvi.65.1.132-137.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Watowich S. S., Yoshimura A., Longmore G. D., Hilton D. J., Yoshimura Y., Lodish H. F. Homodimerization and constitutive activation of the erythropoietin receptor. Proc Natl Acad Sci U S A. 1992 Mar 15;89(6):2140–2144. doi: 10.1073/pnas.89.6.2140. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Wigler M., Pellicer A., Silverstein S., Axel R. Biochemical transfer of single-copy eucaryotic genes using total cellular DNA as donor. Cell. 1978 Jul;14(3):725–731. doi: 10.1016/0092-8674(78)90254-4. [DOI] [PubMed] [Google Scholar]
  27. Witthuhn B. A., Quelle F. W., Silvennoinen O., Yi T., Tang B., Miura O., Ihle J. N. JAK2 associates with the erythropoietin receptor and is tyrosine phosphorylated and activated following stimulation with erythropoietin. Cell. 1993 Jul 30;74(2):227–236. doi: 10.1016/0092-8674(93)90414-l. [DOI] [PubMed] [Google Scholar]
  28. Wolff L., Scolnick E., Ruscetti S. Envelope gene of the Friend spleen focus-forming virus: deletion and insertions in 3' gp70/p15E-encoding region have resulted in unique features in the primary structure of its protein product. Proc Natl Acad Sci U S A. 1983 Aug;80(15):4718–4722. doi: 10.1073/pnas.80.15.4718. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Yang Y. Y., Tojo A., Watanabe N., Amanuma H. Oligomerization of Friend spleen focus-forming virus (SFFV) env glycoproteins. Virology. 1990 Jul;177(1):312–316. doi: 10.1016/0042-6822(90)90485-a. [DOI] [PubMed] [Google Scholar]
  30. Yoshimura A., D'Andrea A. D., Lodish H. F. Friend spleen focus-forming virus glycoprotein gp55 interacts with the erythropoietin receptor in the endoplasmic reticulum and affects receptor metabolism. Proc Natl Acad Sci U S A. 1990 Jun;87(11):4139–4143. doi: 10.1073/pnas.87.11.4139. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Zon L. I., Moreau J. F., Koo J. W., Mathey-Prevot B., D'Andrea A. D. The erythropoietin receptor transmembrane region is necessary for activation by the Friend spleen focus-forming virus gp55 glycoprotein. Mol Cell Biol. 1992 Jul;12(7):2949–2957. doi: 10.1128/mcb.12.7.2949. [DOI] [PMC free article] [PubMed] [Google Scholar]

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