Watanabe D, Ushijima Y, Goshima F, Takakuwa H, Tomita Y, Nishiyama Y
Laboratory of Virology, Research Institute for Disease Mechanism and Control, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
Biochem Biophys Res Commun. 2000 Oct 5;276(3):1248-54. doi: 10.1006/bbrc.2000.3600.
The UL37 gene of herpes simplex virus (HSV) encodes a 120-kDa phosphoprotein associated with the virion. In this study, we have generated a rabbit polyclonal antiserum against HSV-2 UL37 protein, and examined its intracellular localization by immunofluorescence study. In infected cells, specific fluorescence was detectable in the perinuclear region. In transfected cells, UL37 protein was observed mainly in the cytoplasm. Transfection assays of deletion mutants of UL37 protein suggested that the leucine rich region (LRR) containing amino acids 263-273 may be important for cytoplasmic localization. Deletion of the LRR or substitution of the leucine residues resulted in nuclear remaining of UL37 protein. Moreover, the LRR could export green fluorescent protein (GFP) to the cytoplasm as a fusion protein and this export was blocked by leptomycin B treatment, indicating that the LRR acted as a nuclear export signal. These results suggest that UL37 protein fulfills a role as a shuttle between the nucleus and the cytoplasm through the LRR.
单纯疱疹病毒（HSV）的UL37基因编码一种与病毒粒子相关的120 kDa磷蛋白。在本研究中，我们制备了针对HSV-2 UL37蛋白的兔多克隆抗血清，并通过免疫荧光研究检测其细胞内定位。在感染细胞中，可在核周区域检测到特异性荧光。在转染细胞中，UL37蛋白主要在细胞质中观察到。对UL37蛋白缺失突变体的转染分析表明，包含氨基酸263 - 273的富含亮氨酸区域（LRR）可能对细胞质定位很重要。LRR的缺失或亮氨酸残基的替换导致UL37蛋白滞留在细胞核中。此外，LRR可作为融合蛋白将绿色荧光蛋白（GFP）转运到细胞质中，并且这种转运被雷帕霉素B处理所阻断，表明LRR作为核输出信号发挥作用。这些结果表明，UL37蛋白通过LRR在细胞核和细胞质之间发挥穿梭作用。
