Zádori Zoltán, Szelei József, Tijssen Peter
INRS-Institut Armand-Frappier, Université du Québec, Laval, Canada.
J Virol. 2005 Oct;79(20):13129-38. doi: 10.1128/JVI.79.20.13129-13138.2005.
The genomes of all members of the Parvovirus genus were found to contain a small open reading frame (ORF), designated SAT, with a start codon four or seven nucleotides downstream of the VP2 initiation codon. Green fluorescent protein or FLAG fusion constructs of SAT demonstrated that these ORFs were expressed. Although the SAT proteins of the different parvoviruses are not particularly conserved, they were all predicted to contain a membrane-spanning helix, and mutations in this hydrophobic stretch affected the localization of the SAT protein. SAT colocalized with calreticulin in the membranes of the endoplasmic reticulum and the nucleus. A knockout mutant (SAT(-)), with an unmodified VP sequence, showed a "slow-spreading" phenotype. These knockout mutants could be complemented with VP2(-) SAT(+) mutant. The SAT protein is a late nonstructural (NS) protein, in contrast to previously identified NS proteins, since it is expressed from the same mRNA as VP2.
细小病毒属所有成员的基因组中均发现含有一个小开放阅读框（ORF），命名为SAT，其起始密码子位于VP2起始密码子下游4个或7个核苷酸处。SAT的绿色荧光蛋白或FLAG融合构建体表明这些ORF能够表达。尽管不同细小病毒的SAT蛋白并非特别保守，但它们均被预测含有一个跨膜螺旋，且该疏水区域的突变会影响SAT蛋白的定位。SAT在内质网和细胞核膜中与钙网蛋白共定位。一个VP序列未修饰的敲除突变体（SAT(-)）表现出“慢扩散”表型。这些敲除突变体可用VP2(-) SAT(+)突变体进行互补。与先前鉴定的非结构（NS）蛋白不同，SAT蛋白是一种晚期非结构蛋白，因为它与VP2由相同的mRNA表达。
