Chatterjee P K, Vayda M E, Flint S J
EMBO J. 1986 Jul;5(7):1633-44. doi: 10.1002/j.1460-2075.1986.tb04406.x.
The proteins associated with parental, adenoviral DNA in productively-infected HeLa cells have been examined both directly and indirectly. HeLa cells infected with 32P-labelled Ad2 were irradiated with u.v. light at various points in the infectious cycle. Following degradation of the DNA, nuclear proteins carrying cross-linked nucleotides, or oligonucleotides, were distinguished from virion phosphoproteins by the resistance of their 32P radioactivity to 1 M NaOH. The major core protein of the virion, protein VII, was found to be associated with viral DNA throughout infection, even when cells were infected at a multiplicity of 0.14. Micrococcal nuclease digestion of intranuclear viral DNA 4 h after infection liberated two nucleoprotein particles containing viral DNA, neither of which co-migrated with HeLa cell mononucleosomes. These results indicate that core protein VII remains associated with parental adenoviral DNA during productive infections. The observation that protein VII can be cross-linked to DNA in cells infected at very low multiplicity, together with the results of a comparison of proteins cross-linkable to viral DNA in cells infected by wild-type virus and a non-infectious mutant containing the precursor to protein VII, suggest that nucleoproteins comprising viral DNA and protein VII must be the templates for expression of pre-early and early viral genes.
在被有效感染的HeLa细胞中，已对与亲本腺病毒DNA相关的蛋白质进行了直接和间接检测。用32P标记的Ad2感染HeLa细胞，并在感染周期的不同时间点用紫外线照射。DNA降解后，通过其32P放射性对1 M NaOH的抗性，将携带交联核苷酸或寡核苷酸的核蛋白与病毒粒子磷蛋白区分开来。发现病毒粒子的主要核心蛋白VII在整个感染过程中都与病毒DNA相关联，即使细胞以0.14的复数感染时也是如此。感染后4小时对核内病毒DNA进行微球菌核酸酶消化，释放出两个含有病毒DNA的核蛋白颗粒，它们均未与HeLa细胞单核小体共迁移。这些结果表明，在有效感染期间，核心蛋白VII仍与亲本腺病毒DNA相关联。在以非常低的复数感染的细胞中，蛋白VII可与DNA交联这一观察结果，以及对野生型病毒和含有蛋白VII前体的非感染性突变体感染的细胞中可与病毒DNA交联的蛋白质进行比较的结果表明，由病毒DNA和蛋白VII组成的核蛋白必定是早期和早期病毒基因表达的模板。
