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E Kieff

Publications and source records attributed to E Kieff.

At least 199 records · Page 11Linked to original sources
PubMed1981

Epstein-Barr virus DNA. IX. Variation among viral DNAs from producer and nonproducer infected cells.

A comparative analysis of three Epstein-Barr virus DNAs from American patients with infectious mononucleosis (B95-8, Cherry, and Lamont) and four Epstein-Barr virus DNAs from African patients with Burkitt lymphoma (AG876, W91, Raji, and P3HR-1) indicated that the usual format of Epstein-Barr virus DNA includes a variable number of direct repeats of a 0.35 X 10(6)-dalton sequence (TR) at both ends of the DNA, a 9 X 10(6)-dalton sequence of largely unique DNA (Us), a variable number of repeats of a 2 X 10(6)-dalton sequence (IR), and a 89 X 10(6)-dalton sequence of largely unique DNA (UL). Within UL there was homology between DNA at 26 X 10(6) to 28 X 10(6) daltons and DNA at 93 X 10(6) to 95 X 10(6) daltons. The relative sequence order (TR, US, IR, UL, TR) did not vary among "standard" Epstein-Barr virus DNA molecules of each isolate. B95-8 DNA had an unusual deletion extending from 91 X 10(6) to 100 X 10(6) daltons, and P3HR-1 DNA had an unusual deletion extending from 23.5 X 10(6) to 26 X 10(6) daltons. There was sufficient variability among the EcoRI and BamHI fragments of the DNAs to identify each isolate specifically. However, we discerned no distinguishing features for the two geographic or pathogenic origins of the seven isolates. Three intracellular DNAs (Raji, Lamont, and Cherry) and one virion DNA (P3HR-1) were heterogenous in molecular organization and had subpopulations of rearranged or defective molecules. Some regions, particularly 59 X 10(6) to 63 X 10(6) daltons and sequences around TR, frequently participated in rearrangements. Restriction endonuclease maps of the standard and rearranged DNAs of the seven isolates are presented.

Base Sequence↗
PubMed1981

Epstein-Barr virus RNA. VI. Viral RNA in restringently and abortively infected Raji cells.

Nuclear and polyadenylated RNA fractions of Raji cells are encoded by larger fractions of Epstein-Barr virus DNA (35 and 18%, respectively) than encode polyribosomal RNA (10%). Polyribosomal RNA is encoded by DNA mapping at 0.05 X 10(8) to 0.29 X 10(8), 0.63 X 10(8) to 0.66 X 10(8), and 1.10 X 10(8) to 0.03 X 10(8) daltons. An abundant, small (160-base), non-polyadenylated RNA encoded by EcoRI fragment J (0.05 X 10(8) to 0.07 X 10(8) daltons) is also present in the cytoplasm of Raji cells. After induction of early antigen in Raji cells, there was a substantial increase in the complexity of viral polyadenylated and polyribosomal RNAs. Thus, nuclear RNA was encoded by 40% of Epstein-Barr virus DNA, and polyadenylated and polyribosomal RNAs were encoded by at least 30% of Epstein-Barr virus DNA. Polyribosomal RNA from induced Raji cells was encoded by Epstein-Barr virus DNAs mapping at 0.05 X 10(8) to 0.29 X 10(8), 0.63 X 10(8) to 0.66 X 10(8), and 1.10 X 10(8) to 0.03 X 10(8) daltons and also by DNAs mapping within the long unique regions of Epstein-Barr virus DNA at 0.39 X 10(8) to 0.49 X 10(8), 0.51 X 10(8) to 0.59 X 10(8), 0.66 X 10(8) to 0.77 X 10(8), and 1.02 X 10(8) to 1.05 X 10(8) daltons.

Burkitt Lymphoma↗
PubMed1981

Epstein-Barr virus DNA. X. Direct repeat within the internal direct repeat of Epstein-Barr virus DNA.

The 3,360-base-pair internal direct repeat (IR) in Epstein-Barr virus DNA separates the short and long unique DNA domains. IR has a single BamHI site. The juncture between the short unique domain and IR has been mapped by restriction endonucleases and is less than 2,600 nucleotides before the BamHI site in IR. The junction between IR and the long unique domain has been sequenced and is approximately 650 nucleotides after the BamHI site in IR. Thus, relative to the start of IR at the juncture with the short unique domain, the last repeat is at least 90 base pairs short of being complete. There is homology between the 250-nucleotide fragments to the left and the right of the unique BamHI site in IR. A 35-base-pair sequence of the left fragment is directly repeated within the right fragment, once fully and once partially. The implications of these findings are discussed.

DNA Restriction Enzymes↗
PubMed1981

Discordant expression of 2 Epstein-Barr virus-associated antigens, EBNA and RANA, in man-rodent somatic cell hybrids.

The Epstein Barr nuclear antigen (EBNA) and the rheumatoid arthritis nuclear antigen (RANA) develop in human B lymphocytes that have been infected and transformed by Epstein Barr virus (EBV). Antibodies to RANA and EBNA are found only in individuals with prior exposure to EBV. The purpose of the present studies was to determine the relation of the 2 antigens to each other and to EBV genetic material, in human-rodent somatic cell hybrids. Cultured human B lymphoblastoid cells, Raji, Daudi, and RPMI 4098 were fused with thymidine kinase-deficient mouse or hamster fibroblasts. After selection and cloning in ouabain-HAT medium, the hybrid nature of the surviving cells was confirmed by isozyme analysis. The hybrid clones were analyzed for EBNA by anti-complement im,munofluorescence, and for RANA by anti-immunoglobulin immunofluorescence and immunodiffusion. The results showed that RANA and EBNA segregated entirely independently of each other in the hybrid clones. Two methods were used to detect the presence of EBV DNA sequences in the intracellular DNA of hybrid clones. The 1st method relied on the hybridization of labeled cRNA prepared from virion DNA with DNA from 8 hybrid clones affixed to nitrocellulose filters. The 2nd approach was to hybridize labeled intracellular DNA from 3 hybrid clones to Southern blots of cloned fragments of EBV DNA. These results suggested that the presence of EBV DNA was not sufficient for the expression of either antigen. One stable RANA-positive hybrid cell line contained at least 80% of the EBV genome in the absence of detectable EBNA.

Animals↗
PubMed1980

DNA of Epstein-Barr virus VIII: B95-8, the previous prototype, is an unusual deletion derivative.

B95-8, an infectious mononucleosis-derived isolate of Epstein-Barr virus (EBV), is biologically and antigenically indistinguishable from other isolates of EBV and has been the prototype for previous studies of EBV DNA. The long unique region UL of the DNA of a Burkitt tumor isolate, W91, is 9 X 10(6) daltons longer than the UL of B95-8. The "additional DNA and the regions around it have been cloned from W91 and another Burkitt tumor isolate, AG876. The additional DNA is viral and not cellular, since W91 and AG876 have almost identical additional DNA, and there is no detectable homology to human lymphocyte DNA. The insertion site of the additional DNA is within the 0.96 X 10(6) dalton Hinf 1 fragment of B95-8 Bam Hl l. After infection and transformation of five cell lines B95-8 did not pick up additional DNA in this region. Hybridization of labeled DNAs from three EBV-infected cell lines derived from patients with infectious mononucleosis to blots of fragments of the additional DNA indicates that these sequences are present in American as well as in African virus. B95-8 is therefore an unusual deletion derivative. A newly discovered feature of EBV DNAs is that sequences which map near the left end of UL have homology to part of the additional DNA.

Animals↗
PubMed1980

Epstein-Barr virus (B95-8) DNA VII: molecular cloning and detailed mapping.

Two of the Sal I fragments and all of the internal BamHI fragments (with the exception of BamHI c, a 0.6 x 10(6) dalton fragment) of Epstein-Barr virus (EBV) DNA have been cloned in pBR322. The termini and other parts of the DNA (including the EcoRI fragment which contains BamHI c) have been cloned as EcoRI fragments in bacteriophage Charon 4A. The cloned DNAs have been used to derive a complete map of the BamHI fragments of EBV DNA and to align the BamHI, EcoRI, HindIII, and SalI cleavage sites in EBV DNA.

Bacteriocin Plasmids↗
PubMed1980

Epstein-Barr virus RNA. V. Viral RNA in a restringently infected, growth-transformed cell line.

A continuous lymphoblastoid cell line, IB-4, was established by infection and growth transformation of normal neonatal B lymphocytes with the B95-8 isolate of Epstein-Barr virus (EBV). The IB-4 cells contained the intranuclear antigen, EBNA, but not early antigen, EA. The fragments produced by the digestion of intracellular episomal viral DNA (density, 1.700 to 1.720 g/cm3) with EcoRI restriction endonuclease were identical in size to the A, B, C, E, F, G, and H fragments of virion DNA. As expected from the previous observation that episomal intracellular DNA is circular, the fragment containing the rightward terminal sequences of EBV DNA in IB-4 cells was larger than the corresponding fragment of linear viral DNA, probably as a consequence of covalent linkage to the leftward terminal fragment. Also, two fragments, EcoRI-I and -J, which were adjacent to each other in the virion DNA, were absent from the intracellular DNA. The labeled EcoRI-J of viral DNA hybridized instead to a new fragment equal in size to EcoRI-I and -J combined. Analysis of viral RNA in IB-4 cells showed that RNAs encoded by more than 30% of the viral DNA comprised approximately 0.06% of the nuclear RNA, whereas RNAs encoded by 20% and 10% of the viral DNA comprised approximately 0.06% and 0.003% of the polyadenylated and polyribosomal RNAs, respectively. Viral mRNA (polyribosomal RNA) was encoded by DNA which mapped at 0.05 x 10(8) to 0.36 x 10(8) daltons and to a lesser extent by DNAs which mapped at 0.62 x 10(8) to 0.67 x 10(8), 0.70 x 10(8) to 0.73 x 10(8), and 1.13 x 10(8) to 1.15 x 10(8) daltons in the B95-8 genome. The most agundant nuclear viral RNAs were encoded primarily by DNA which mapped at the same loci; but RNAs encoded by many other fragments of viral DNA could also be detected among nuclear RNAs. Viral mRNA(s) (polyribosomal) was encoded by about 40% of the internal reiteration and by 25% of the BamHI-H fragments which mapped from 0.32 x 10(8) to 0.36 x 10(8) daltons, nuclear RNAs were encoded by at least 57% of the internal reiteration and 40% of BamHI-H. These data indicate that there is selective accumulation of some viral RNAs within the nucleus of IB-4 cells and that there is selective post-transcriptional processing of these RNAs. Finer mapping of the DNA which encodes mRNA (polyribosomal) in IB-4 cells indicated that some of this DNA is deleted in the DNA of the P3 HR-1 virus, the only isolate of EBV which cannot initiate growth transformation. These data, therefore, support the hypothesis that expression of this region of EBV genome is important for growth transformation or for the maintenance of restrigent infection.

B-Lymphocytes↗
PubMed1979

Epstein-Barr virus-specific RNA. III. Mapping of DNA encoding viral RNA in restringent infection.

Namalwa and Raji cells, originally obtained from a Burkitt tumor biopsy, grow as continuous cell lines in vitro and contain the Epstein-Barr virus (EBV)-related nuclear antigen EBNA (B. M. Reedman and G. Klein, Int. J. Cancer 11:499-520, 1973) and RNA homologous to at least 17 and 30% of the EBV genome, respectively (S. D. Hayward and E. Kieff, J. Virol. 18:518-525, 1976; T. Orellana and E. Kieff, J. Virol. 22:321-330, 1977). The polyribosomal and polyadenylated [poly(A)+] RNA fractions of Namalwa and Raji cells are enriched for a class of viral RNA homologous to 5 to 7% of EBV DNA (Hayward and Kieff, J. Virol. 18:518-525, 1976; Orellana and Kieff, J. Virol. 22:321-330, 1977). The objective of the experiments described in this communication was to determine the location within the map of the EBV genome (D. Given and E. Kieff, J. Virol. 28:524-542, 1978) of the DNA which encodes the viral RNA in the poly(A)+ and non-polyadenylated [poly(A)-] RNA fractions of Namalwa cells. Hybridization of labeled DNA homologous to Namalwa poly(A)+ or poly(A)- RNA to blots containing EcoRI, Hsu I, or Hsu I/EcoRI double-cut fragments of EBV (B95-8) or (W91) DNA indicated that these RNAs are encoded by DNA contained primarily in the Hsu I A/EcoRI A and Hsu I B/EcoRI A fragments and, to a lesser extent, in other fragments of the EBV genome. Hybridizations of Namalwa poly(A)+ and poly(A)- RNA in solution to denatured labeled EcoRI A or B fragments, Hsu I A, B, or D fragments, and Hsu I A/EcoRI A or Bam I S fragments and of Raji polyribosomal poly(A)+ RNA to the EcoRI A fragment indicated that (i) Namalwa poly(A)+ RNA is encoded primarily by 6 x 10(5) daltons of a 2 x 10(6)-dalton segment of DNA, Bam I S, which is tandemly reiterated, approximately 10 times, in the Hsu I A/EcoRI A fragment and is encoded to a lesser extent by DNA in the Hsu I B, EcoRI B, and Hsu I D fragments. Raji polyribosomal poly(A)+ RNA is encoded by a similar fraction of the EcoRI A fragment as that which encodes Namalwa poly(A)+ RNA. (ii) The fraction of the Bam I S fragment homologous to Namalwa poly(A)- RNA is similar to the fraction homologous to Namalwa poly(A)+ RNA. However, Namalwa poly(A)- RNA is homologous to a larger fraction of the DNA in the Hsu I B, Hsu I D, and EcoRI B fragments.

Cell Line↗
PubMed1979

DNA of Epstein-Barr virus. V. Direct repeats of the ends of Epstein-Barr virus DNA.

Previous data indicated that Epstein-Barr virus DNA is terminated at both ends by direct or inverted repeats of from 1 to 12 copies of a 3 X 10(5)-dalton sequence. Thus, restriction endonuclease fragments which include either terminus vary in size by 3 X 10(5)-dalton increments (D. Given and E. Kieff, J. Virol. 28:524--542, 1978; S. D. Hayward and E. Kieff, J. Virol. 23:421--429, 1977). Furthermore, defined fragments containing either terminus hybridize to each other (Given and Kieff, J. Virol. 28:524--542, 1978). The 5' ends of the DNA are susceptible to lambda exonuclease digestion (Hayward and Kieff, J. Virol. 23:421--429, 1977). To determine whether the terminal DNA is a direct or inverted repeat, the structures formed after denaturation and reannealing of the DNA from one terminus and after annealing of lambda exonuclease-treated DNA were examined in the electron microscope. The data were as follows. (i) No inverted repeats were detected within the SalI D or EcoRI D terminal fragments of Epstein-Barr virus DNA. The absence of "hairpin- or pan-handle-like" structures in denatured and partially reannealed preparations of the SalI D or EcoRI D fragment and the absence of repetitive hairpin- or pan-handle-like structures in the free 5' tails of DNA treated with lambda exonuclease indicate that there is no inverted repeat within the 3 X 10(5)-dalton terminal reiteration. (ii) Denatured SalI D or EcoRI D fragments reanneal to form circles ranging in size from 3 X 10(5) to 2.5 X 1O(6) daltons, indicating the presence of multiple direct repeats within this terminus. (iii) Lambda exonuclease treatment of the DNA extracted from virus that had accumulated in the extracellular fluid resulted in asynchronous digestion of ends and extensive internal digestion, probably a consequence of nicks and gaps in the DNA. Most full-length molecules, after 5 min of lambda exonuclease digestion, annealed to form circles, indicating that there exists a direct repeat at both ends of the DNA. (iv) The finding of several circularized molecules with small, largely double-strand circles at the juncture of the ends indicates that the direct repeat at both ends is directly repeated within each end. Hybridization between the direct repeats at the termini is likely to be the mechanism by which Epstein-Barr virus DNA circularizes within infected cells (T. Lindahl, A. Adams, G. Bjursell, G. W. Bornkamm, C. Kaschka-Dierich, and U. Jehn, J. Mol. Biol. 102:511-530, 1976).

Animals↗
PubMed1979

DNA of Epstein-Barr virus. VI. Mapping of the internal tandem reiteration.

Epstein-Barr virus (B95-8) DNA consists of short (10 X 10(6)) and long (87 X 10(6)) unique DNA sequences joined by 10 tandem reiterations of a 1.85 X 10(6) DNA segment. The reiterated sequence contains BamI and BglII sites separated by 4 X 10(5). The 4.5 X 10(5) and 14.0 X 10(5) segments generated by cleavage of the reiterated DNA with BamI and BglII contain sequences which hybridize to each other, suggesting that the internal tandemly reiterated sequence has a direct or inverted repeat within it. The opposite ends of the linear, nicked, double-stranded DNA molecule (R. F. Pritchett, S. D. Hayward, and E. D. Kieff, J. Virol. 15:556--569, 1975) consist of from 1 to 12 direct repeats of another 3 X 10(5) sequence (D. Given and E. Kieff, J. Virol. 28:524--542, 1978; D. Given, D. Yee, K. Griem, and E. Kieff, J. Virol. 30:852--862, 1979). There is no homology between the internal reiterated sequence and either terminus. However, part of the internal reiteration (less than 5 X 10(5) is reiterated at two separate locations in the long unique region. The internal reiterations are a source of variation within EBV (B95-8) DNA preparations. Thus, although the majority of molecules contain 10 tandem reiterations, some molecules have 9, 8, 7, 6, 5, 4, or fewer tandem reiterations. A consequence of this variability is that the KpnI A fragment and the EcoRI/Hsul A fragment consist of a family of seven or more fragments differing in the number of tandem internal reiterations. The EcoRI/HsuI A fragment of EBV (W91) DNA is approximately 6 X 10(6) smaller than the largest and dominant EcoRI/HsuI A fragment of EBV (B95-8) DNA. EBV (W91 DNA also differs from EBV (B95-8) DNA by an additional 7 X 10(6) to 8 X 10(6) of DNA in the long unique DNA region (D. Given and E. Kieff, J. Virol. 28:524--542, 1978; N. Raab-Traub, R. Pritchett, and E. Kieff, J. Virol. 27:388--398, 1978). These data suggest the possibility that the smaller number of internal reiterations in EBV (W91) DNA may be a consequence of the additional unique DNA and a restriction in the overall size of EBV DNA.

Base Sequence↗
PubMed1978

DNA of Epstein-Barr virus. III. Identification of restriction enzyme fragments that contain DNA sequences which differ among strains of Epstein-Barr virus.

Previous kinetic and absorption hybridization experiments had demonstrated that the DNA of the B95-8 strain of Epstein-Barr virus was missing approximately 10% of the DNA sequences present in the DNA of the HR-1 strain (R.F. Pritchett, S.D. Hayward, and E. Kieff, J. Virol. 15:556-569, 1975; B. Sugder, W.C. Summers, and G. Klein, J. Virol. 18:765-775, 1976). The HR-1 strain differs from other laboratory strains, including the B95-8 and W91 strains, and from virus present in throat washings from patients with infectious mononucleosis in its inability to transform lymphocytes into lymphoblasts capable of long-term growth in culture (P. Gerber, Lancet i:1001, 1973; J. Menezes, W. Leibold, and G. Klein, Exp. Cell. Res. 92:478-484, 1975; G. Miller, D. Coope, J. Niederman, and J. Pagano, J. Virol. 18:1071-1080, 1976; G. Miller, J. Robinson, L. Heston, and M. Lipman, Proc. Natl. Acad. Sci. U.S.A. 71:4006-4010, 1974). In the experiments reported here, the restriction enzyme fragments of Epstein-Barr virus DNA which contain sequences which differ among the HR-1, B95-8, and W91 strains have been identified. The DNA of the HR-1, B95-8, and W91 strains each differed in complexity. The sequences previously shown to be missing in the B95-8 strain were contained in the EcoRI-C and -D and Hsu I-E and -N fragments of the HR-1 strain and in the EcoRI-C and Hsu I-D and -E fragments of the W91 strain. The HR-1 strain was missing DNA contained in EcoRI fragments A and J through K and Hsu I fragment B of the B95-8 strain and in the EcoRI-A and Hsu I-B fragments of the W91 strain. The relationship of these data to the linkage map of restriction enzyme fragments of the DNA of the B95-8 and W91 strains (E. Kieff, N. Raab-Traub, D. Given, W. King, A.T. Powell, R. Pritchett, and T. Dambaugh, In F. Rapp and G. de-The, ed., Oncogenesis and Herpesviruses III, in press; D. Given and E. Kieff, submitted for publication) and the possible significance of the data are discussed.

Base Sequence↗
PubMed1978

DNA of Epstein-Barr virus. IV. Linkage map of restriction enzyme fragments of the B95-8 and W91 strains of Epstein-Barr Virus.

The arrangement of EcoRI, Hsu I, and Sal I restriction enzyme sites in the DNA of the B95-8 and W91 isolates of Epstein-Barr virus (EBV) has been determined from the size of the single-enzyme-cleaved fragments and from blot hybridizations that identify which fragments cut from the DNA with one enzyme contain nucleotide sequences in common with fragments cut from the DNA with a second enzyme. The DNA of the B95-8 isolate was the prototype for this study. The data indicate that (i) approximately 95 X 10(6) to 100 X 10(6) daltons of EBV (B95-8) DNA is in a consistent and unique sequence arrangement. (ii) Both termini are variable in length. One end of the molecule after Hsu I endonuclease cleavage consists of approximately 3,000 base pairs, with as many as 10 additional 500-base pair segments. The opposite end of the molecule after Sal I endonuclease cleavage consists of approximately 1,500 base pairs, with as many as 10 additional 500-base pair segments. (iii) The opposite ends of the molecule contain homologous sequences. The high degree of homology between the opposite ends of the molecule and the similarity in size of the "additional" 500-base pair segments suggests that there are identical repeating units at both ends of the DNA. The arrangement of restriction endonuclease fragments of the DNA of the W91 isolate of EBV is similar to that of the B95-8 isolate and differs from the latter in the presence of approximately 7 X 10(6) daltons of "extra" DNA at a single site. Thus, the size of almost all EcoRI, Hsu I, and Sal I fragments of EBV (W91) DNA is identical to that of fragments of EBV (B95-8) DNA. A single EcoRI fragment, C, of EBV (W91) DNA is approximately 7 X 10(6) daltons larger than the corresponding EcoRI fragment of EBV (B95-8) DNA. Digestion of EBV (W91) DNA with Hsu I or Sal I restriction endonucleases produces two fragments (Hsu I D1 and D2 or Sal I G2 and G3) which differ in total size by approximately 7 X 10(6) daltons from the fragments of EBV (B95-8) DNA. Furthermore, the EcoRI, Hsu I, and Sal I fragments of EBV (W91) and (B95-8) DNAs, which are of similar molecular weight, have homologous nucleotide sequences. Moreover, the W91 fragments contain only sequences from a single region of the B95-8 genome. Two lines of evidence indicate that the "extra" sequences present in W91 EcoRI fragment C are viral DNA and not cellular. (i) The molecular weight of the "enlarged" EcoRI C fragment of EBV (W91) DNA is identical to that of the EcoRI C fragment of another isolate of EBV (Jijoye), (ii) The HR-1 clone of Jijoye has previously been shown to contain DNA which is not present in the B95-8 strain but is present in the EcoRI C and Hsu I D2 and D1 fragments of EBV (W91) DNA (N. Raab-Traub, R. Pritchett, and E. Kieff, J. Virol. 27:388-398, 1978).

Cell Line↗
PubMed1978

Mapping of putative transforming sequences of EBV DNA.

The linkage of restriction enzyme fragments of DNA of the B95-8 strain of Epstein-Barr virus has been determined. Two approaches are being employed to define which EBV DNA sequences are needed to initiate and maintain the transformation of lymphocytes to lymphoblasts capable of long-term growth in culture. The first approach is to determine the differences between the DNA of strains of EBV which possess transforming capacity and the DNA of the HR-1 strain which cannot transform. The data indicate that EBV (HR-1) DNA lacks approximately 2--3 x 10(6) daltons of DNA contained largely in the HsuI B and EcoRI (J-K) and A fragments of EBV (B95-8) DNA and in the EcoRI A and HsuI B fragment of the W91 strain. The DNA common to HsuI B and EcoRI A fragments lies between 27 and 42 x 10(6) daltons from the HsuI A end of the molecule. This finding is compatible with the hypothesis that the inability of the HR-1 strain to transform is due to the absence of DNA needed for transformation. The second approach is to identify and map the DNA encoding polyadenylated viral RNA in cultures of restringently infected cells which contain the EBNA antigen and show no evidence of abortive or productive infection. Previous data indicated that viral RNA species encoded by 5% of the viral DNA are adenylated and identified in the polyribosomes of restringently infected cells. The data indicate that these RNAs are encoded primarily by the HsuI A (and to a lesser extent, B) fragment of EBV (B95-8) DNA. This would place the DNA encoding the viral RNA processed in restrigently infected cells adjacent to and possibly overlapping the small DNA segment deleted from the DNA of the non-transforming HR-1 strain.

Base Sequence↗
PubMed1977

Epstein-barr virus-specific RNA. II. Analysis of polyadenylated viral RNA in restringent, abortive, and prooductive infections.

The complexity and abundance of Epstein-Barr (EBV)-specific RNA in cell cultures restringently, abortively, and productively infected with EBV has been analyed by hybridization of the infected cell RNA with purified viral DNA. The data indicate the following. (i) Cultures containing productively infected cells contain viral RNA encoded by at least 45% of EBV DNA, and almost all of the species of viral RNA are present in the polyadenylated and polyribosomal RNA fractions. (ii) Restringently infected Namalwa and Raji cultures, which contain only intranuclear antigen, EBNA, and enhanced capacity for growth in vitro, contain EBV RNA encoded by at least 16 and 30% of the EBV DNA, respectively. The polyadenylated and polyribosomal RNA fractions of Raji and Namalwa cells are enriched for a class of EBV RNA encoded by approximately 5% of EBV DNA. The same EBV DNA sequences encode the polyadenylated and polyribosomal RNA of both Raji and Namalwa cells. (iii) After superinfection of Raji cultures with EBV (HR-1), the abortively infected cells contain RNA encoded by at least 41% of EBV DNA. The polyadenylated RNA of superinfected Raji cells is enriched for a class of EBV RNA encoded by approximately 20% of EBV HR-1 DNA. Summation hybridization experiments suggest that the polyadenylated RNA in superinfected Raji cells is encoded by the same DNA sequences as encode RNA present in Raji cells before superinfection, most of which is not polyadenylated. That the same EBV RNA sequences are present in the polyadenylated and polyribosomal fractions of two independently derived, restringently infected cell lines suggests that these RNAs may specify functions related to maintenance of the transformed state. The complexity of this class of RNA is adequate to specify a sequence of a least 5,000 amino acids. That only some RNA species are polyadenylated in restringent and abortive infection suggests that polyadenylation or whatever determines polyadenylation may play a role in the restricted expression of the EVB genome.

Base Sequence↗
PubMed1977

DNA of Epstein-Barr virus. II. Comparison of the molecular weights of restriction endonuclease fragments of the DNA of Epstein-Barr virus strains and identification of end fragments of the B95-8 strain.

Incubation of the DNA of the B95-8 strain of Epstein-Barr virus [EBV (B95-8) DNA] with EcoRI, Hsu I, Sal I, or Kpn I restriction endonuclease yielded 8 to 15 fragments separable on 0.4% agarose gels and ranging in molecular weight from less than 1 to more than 30 x 10(6). Bam I and Bgl II yielded fragments smaller than 11 x 10(6). Preincubation of EBV (B95-8) DNA with lambda exonuclease resulted in a decrease in the Hsu I A and Sal I A and D fragments, indicating that these fragments are positioned near termini. The electrophoretic profiles of the fragments produced by cleavage of the DNA of the B95-8, HR-1, and Jijoye strains of EBV were each distinctive. The molecular weights of some EcoRI, Hsu I, and Sal I fragments from the DNA of the HR-1 strain of EBV [EBV (HR-1) DNA] and of EcoRI fragments of the DNA of the Jijoye strain of EBV were identical to that of fragments produced by cleavage of EBV (B95-8) DNA with the same enzyme, whereas others were unique to each strain. Some Hsu I, EcoRI, and Sal I fragments of EBV (HR-1) DNA and Kpn I fragments of EBV (B95-8) DNA were present in half-molar abundance relative to the majority of the fragments. In these instances, the sum of the molecular weights of the fragments was in excess of 10(8), the known molecular weight of EBV (HR-1) and (B95-8) DNA. The simplest interpretation of this finding is that each EBV (HR-1), and possibly also (B95-8), DNA preparation contains two populations of DNA molecules that differ in the arrangement of DNA sequences about a single point, such as has been described for herpes simplex virus DNA. Minor fragments could also be observed if there were more than one difference in primary structure of the DNAs. The data do not exclude more extensive heterogeneity in primary structure of the DNA of the HR-1 strain. However, the observation that the relative molar abundance of major and minor fragments of EBV (HR-1) DNA did not vary between preparations from cultures that had been maintained separately for several years favors the former hypothesis over the latter.

Cell Line↗