A baculovirus-encoded protein tyrosine phosphatase gene induces enhanced locomotory activity in a lepidopteran host
A baculovirus-encoded protein tyrosine phosphatase gene induces enhanced locomotory activity in a lepidopteran host
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DOI：
10.1073/pnas.0409457102
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发表时间：
2005-02-15
影响因子：
11.1
通讯作者：
Hammock, BD
中科院分区：
文献类型：
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作者：
Kamita, SG;Nagasaka, K;Hammock, BD
增强的运动活动（ELA），如游走，是鳞翅目（蝴蝶和蛾）昆虫幼虫阶段结束时发生的正常行为。杆状病毒感染也能诱导鳞翅目幼虫的ELA。人们相信，病毒诱导这种行为，以增加其传播[Goulson，D.（1997）Oecologia 109，219-228]。在这里，我们表明，杆状病毒编码的蛋白酪氨酸磷酸酶（PTP）基因（PTP）诱导ELA，是由光激活。用杆状病毒B感染家蚕，诱导ELA。家蚕核型多角体病毒（BmNPV）在感染后约3.75天（p.i.）并持续至感染后4.75天。ELA的强度在感染后5.25天死亡前立即显著降低。光激活ELA的强度约为3倍，与ELA的幼虫表现出积极的向光性。B的幼虫不诱导ELA。感染BmNPVptp敲除突变体（BmPTPD）的mori。然而，当蚕衍生的ptp基因（Bmptp-h）插入BmPTPD，ELA部分恢复。在自然游走阶段开始后2天，从家蚕中鉴定出Bmptp-h。Bmptp-h的氨基酸序列与家蚕核型多角体病毒（BmNPV）ptp的氨基酸序列同源性为48.2%（80.7%）。的高度同源性和幼虫阶段的基础上，Bmptp-h被隔离，我们假设，现代杆状病毒可能已经获得了其PTP基因从祖先的主机，这个基因被选择性地保持，因为它增加了病毒的传播。
Enhanced locomotory activity (ELA), such as wandering, is a normal behavior that occurs at the end of the larval stage in lepidopteran (butterflies and moths) insects. Baculovirus infection can also induce ELA in lepidopteran larvae. The belief is that the virus induces this behavior to increase its transmission [Goulson, D. (1997) Oecologia 109, 219-228]. Here we show that a baculovirus-encoded protein tyrosine phosphatase (PTP) gene (ptp) induces ELA that is activated by light. ELA was induced in silkworm Bombyx mori infected with the baculovirus B. mori nucleopolyhedrovirus (BmNPV) beginning at approximate to 3.75 days postinfection (p.i.) and continued until 4.75 days p.i. The intensity of the ELA was dramatically reduced immediately before death at 5.25 days p.i. Light activated the intensity of the ELA by approximate to 3-fold, and larvae with ELA showed positive phototropism. ELA was not induced in larvae of B. mori infected with a BmNPV ptp knockout mutant (BmPTPD). However, when a silkworm-derived ptp gene (Bmptp-h) was inserted into BmPTPD, ELA was partially recovered. Bmptp-h was identified from silkworms at 2 days after the start of the natural wandering stage. The deduced amino acid sequence of Bmptp-h showed 48.2% identify (80.7% similarity) to the deduced amino acid sequence of BmNPV ptp. On the basis of the high homology and larval stage at which Bmptp-h was isolated, we postulate that the modern baculovirus may have acquired its ptp gene from an ancestral host and that this gene was selectively maintained because it increases virus transmission.