Friend strain of spleen focus-forming virus is a recombinant between ecotropic murine type C virus and the env gene region of xenotropic type C virus.

Troxler, D H; Lowy, Douglas R.; Howk, Richard; Young, Howard A.; Scolnick, Edward M.

doi:10.1073/pnas.74.10.4671

Cited by 106 publications

(88 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The MCF viruses are suspect because (a) they have been isolated only from late preleukemic or leukemic mice, (b) they are found only in the thymus of late preleukemic AKR mice (the thymus being the target organ in spontaneous AKR lymphoma), and (c) they are associated with many of the widely used leukemogenic laboratory MuLV strains (Friend, Moloney, Rauscher) (8,14) (M. W. Cloyd, J. W. Hartley, and W. P. Rowe. Unpublished data.).…”

mentioning

confidence: 99%

Lymphomagenicity of recombinant mink cell focus-inducing murine leukemia viruses.

Cloyd

Hartley

Rowe

1980

The Journal of Experimental Medicine

298

219

View full text Add to dashboard Cite

Recombinant mink cell focus-inducing (MCF) murine leukemic viruses, as well as ecotropic and xenotropic viruses, were tested for ability to accelerate or cause development of lymphoma in AKR and other strains of mice. Of the three classes of virus isolated from AKR, only the MCF viruses were able to accelerate development of AKR lymphoma. This fully supports the idea that the MCF viruses are the proximal cause of spontaneous AKR lymphoma. MCF lymphomagenicity was strain specific, however, in that AKR MCF viruses did not induce lymphomas in many murine strains; they were moderately lymphomagenic in C3H/Bi mice and in National Institutes of Health Swiss partially congenic for Akv-1 or Akv-2. In contrast, MCF viruses from nonthymic hematopoietic neoplasms of C3H/Fg, BALB/c, or mice partially congenic for ecotropic virus loci (Akv-1, Akv-2, Fgv-1, C58v-1, and C58v-2) were not able to accelerate or cause lymphomia in AKR or any other mouse strain tested, including some of the strains of origin. MCF lymphomagenicity correlated with thymic origin in the virus and with ability to replicate in the thymus.

show abstract

mentioning

confidence: 99%

Lymphomagenicity of recombinant mink cell focus-inducing murine leukemia viruses.

Cloyd

Hartley

Rowe

1980

The Journal of Experimental Medicine

298

219

View full text Add to dashboard Cite

show abstract

“…The allele at this locus determines virus host range, and differences between highly leukemogenic viruses and their more benign relatives cluster within this gene (2)(3)(4)(5)(6)(7). The primary protein product of the Moloney murine leukemia virus (Mo-MuLV) env gene is a glycosylated molecule that has an apparent Mr 80,000 (Pr80e"v) (8).…”

mentioning

confidence: 99%

Sequence-specific antibodies show that maturation of Moloney leukemia virus envelope polyprotein involves removal of a COOH-terminal peptide.

Green¹,

Shinnick²,

Witte³

et al. 1981

Proc. Natl. Acad. Sci. U.S.A.

141

113

View full text Add to dashboard Cite

We followed maturation of the glycosylated envelope polyprotein Pr8Ovofa murine retrovirus by using antisera specific to subregions of the protein, including an antiserum directed against a synthetic peptide corresponding to the COOHterminus of Pr80. Shortly after synthesis and glycosylation, Pr8Ov is cleaved into two species, gp7O and Pr15E, that are found associated, perhaps through disulfide bonds, in infected cells. PrISE is further cleaved at the time of virus maturation to form virus protein pl5E. NH2-Terminal protein sequence analysis showed that PriSE had, an NH2 terminus in common with pl5E. Pr15E, but not plSE, is precipitated by antibody against the COOH-terminal peptide; hence, pl5E is missing a peptide at the COOH-terminus. Our data indicate that Pr15E is the predominant species in cells and pl5E is the major species in virus.The envelope (env) gene ofmurine retroviruses encodes a polymorphic family of proteins (1). The allele at this locus determines virus host range, and differences between highly leukemogenic viruses and their more benign relatives cluster within this gene (2-7). The primary protein product of the Moloney murine leukemia virus (Mo-MuLV) env gene is a glycosylated molecule that has an apparent Mr 80,000 (Pr80e"v) (8). The Pr80env polyprotein contains the information (NH2 to COOH terminal) for gp7O, the major envelope glycoprotein; pl5E, a second viral membrane protein; and R, a COOH-terminal species (9, 10). This report describes the intermediates and end products of Pr80env processing and their times of appearance. We present evidence that the COOH-terminal peptide is removed during the formation ofmature virions and may function in virus assembly..From the data presented here-and the work of others (9, 11-15), a scheme for env precursor processing emerges. After glycosylation of the primary env translation product, the resulting Pr80env molecule is cleaved into two products. One is derived from the NH2-terminal region and contains gp70; the other contains the COOH-terminal 196 amino acids. All of the carbohydrate chains are attached to the gp7O portion. (R-MuLV) were labeled with [3S]methionine similarly. Immune precipitation and one-dimensional gel electrophoresis were performed as described (13). Antisera used for immune precipitation were as follows: (i) anti-gp70, raised against gp7O purified from RMuLV (17); (ii) anti-plSE raised against pl5E purified from RMuLV (a gift from I. Fleissner); (iii) anti-plSE ascitic fluid from hybridoma 9E8, (a gift from R. Nowinski; ref. 18; and (iv) To 10 dul of the supernatant was added 1 A1 of bovine serum albumin in sample buffer (5 ,ug/ml) as an internal standard, 22 ,1 of sample dilution buffer (9.5 M urea/2% ampholines, pH 3.5-10/5% 2-mercaptoethanol/8% Nonidet P-40), and 8.25 mg of solid urea to bring the final concentration of urea to 9.5 M.Abbreviations: Mo-MuLV and R-MuLV, Moloney and Rauscher murine leukemia virus, respectively.

show abstract

“…Cell lines and viruses were clonally isolated as previously described (18,25,33,34). These materials included the following: BALB/c/3T3 murine fibroblasts infected either with Rauscher murine leukemia virus (MuLV) (R-BALB cells) (34) or with the Lilly-Steeves polycythemia strain of Friend spleen focus-forming virus (SFFV) (BALB clone 4 cells) (38); NIH/3T3 murine fibroblasts infected with wild-type or mutant Friend SFFV (32): normal rat kidney fibroblasts infected with either Friend SFFV (NRK clone 1 cells) (34. 38) or Friend MuLV (F12 NRK cells) (18); Sc-I murine fibroblasts infected with the dual tropic MCF 247 MuLV (25) (10 ,ug) were electrophoresed in a horizontal 1.5% agarose gel containing 10 mM methyl mercuric hydroxide, blot transferred to diazophenylthioether paper.…”

Section: Methodsmentioning

confidence: 99%

Frequent hereditable shutdown of murine retrovirus gene expression in murine cell lines.

Bestwick¹,

Machida²,

Polonoff³

et al. 1984

Mol. Cell. Biol.

View full text Add to dashboard Cite

Friend spleen focus-forming virus shuts down its gene expression frequently (ca. 10-3 per generation) in a cis-dominant hereditable fashion in various murine cells but much less frequently in rat cells (less than 10-6 per generation). Thus. nonexpresser variants were isolated at high frequency from murine cell lines by immunoselection directed against virus-encoded cell surface glycoproteins and also simply by subcloning cells from lines which had been cultured for many generations. Studies of independently infected cell clones indicate that shutdown is a property of the cell line rather than of the specific proviral site. Nucleic acid blot analyses suggest that shutdown correlates with decreased transcription. Moreover, preliminary evidence indicates that other murine retroviruses also shut down frequently in murine but not

show abstract

Friend strain of spleen focus-forming virus is a recombinant between ecotropic murine type C virus and the env gene region of xenotropic type C virus.

Cited by 106 publications

References 23 publications

Lymphomagenicity of recombinant mink cell focus-inducing murine leukemia viruses.

Lymphomagenicity of recombinant mink cell focus-inducing murine leukemia viruses.

Sequence-specific antibodies show that maturation of Moloney leukemia virus envelope polyprotein involves removal of a COOH-terminal peptide.

Frequent hereditable shutdown of murine retrovirus gene expression in murine cell lines.

Contact Info

Product

Resources

About