van Oers M M, Flipsen J T, Reusken C B, Sliwinsky E L, Goldbach R W, Vlak J M
Department of Virology, Wageningen Agricultural University, The Netherlands.
J Gen Virol. 1993 Apr;74 ( Pt 4):563-74. doi: 10.1099/0022-1317-74-4-563.
Distinct functional domains in the Autographa californica nuclear polyhedrosis virus p10 protein were identified by analysis of p10 mutants. When up to 15 amino acids from the carboxy terminus were deleted, truncated p10 proteins were found in both the nucleus and the cytoplasm of infected cells, but formed no fibrillar structures. This suggested that the positively charged carboxy terminus is not required for nuclear or cytoplasmic localization of p10 protein, but is involved in protein-protein interactions leading to assembly of the p10 protein into fibrillar structures. Absence of the p10 protein prevented the release of polyhedra from infected cells, caused by impaired nuclear disintegration. This function of the p10 protein appears to be located between amino acid residues 52 and 79. The amino-terminal half of the p10 protein has already been implicated in the self-aggregation of this protein. Thus fibrillar structure formation, nuclear disintegration and intermolecular p10 protein interactions seem to be three separate functions of the p10 protein and these functions are located in distinct domains of the protein. The mutants expressing truncated p10 proteins were impaired in electron-dense spacer formation but polyhedron envelopes were still formed. This result suggested that the formation of electron-dense spacers is not a prerequisite for the formation of polyhedron envelopes.
通过对p10突变体的分析，确定了苜蓿银纹夜蛾核型多角体病毒p10蛋白中不同的功能结构域。当从羧基末端缺失多达15个氨基酸时，在受感染细胞的细胞核和细胞质中均发现了截短的p10蛋白，但未形成纤维状结构。这表明带正电荷的羧基末端对于p10蛋白在细胞核或细胞质中的定位不是必需的，但参与了导致p10蛋白组装成纤维状结构的蛋白质-蛋白质相互作用。p10蛋白的缺失阻止了多角体从受感染细胞中的释放，这是由核解体受损引起的。p10蛋白的这一功能似乎位于氨基酸残基52和79之间。p10蛋白的氨基末端一半已被认为与该蛋白的自我聚集有关。因此，纤维状结构形成、核解体和分子间p10蛋白相互作用似乎是p10蛋白的三个独立功能，这些功能位于该蛋白的不同结构域中。表达截短p10蛋白的突变体在电子致密间隔形成方面受损，但仍形成多角体包膜。这一结果表明，电子致密间隔的形成不是多角体包膜形成的先决条件。
