Novel Type II Transmembrane Serine Proteases, MSPL and TMPRSS13, Proteolytically Activate Membrane Fusion Activity of the Hemagglutinin of Highly Pathogenic Avian Influenza Viruses and Induce Their Multicycle Replication
Novel Type II Transmembrane Serine Proteases, MSPL and TMPRSS13, Proteolytically Activate Membrane Fusion Activity of the Hemagglutinin of Highly Pathogenic Avian Influenza Viruses and Induce Their Multicycle Replication
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DOI：
10.1128/jvi.02605-09
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发表时间：
2010-05-01
影响因子：
5.4
通讯作者：
Kido, Hiroshi
中科院分区：
文献类型：
--
作者：
Okumura, Yuushi;Takahashi, Etsuhisa;Kido, Hiroshi
宿主细胞蛋白酶通过切割病毒表面包膜糖蛋白血凝素（HA）诱导流感病毒进入细胞。然而，关于参与该事件的细胞蛋白酶的详细信息尚不完全可用。我们在这里报告，无处不在的II型跨膜丝氨酸蛋白酶，MSPL及其剪接变体TMPRSS 13，是新的候选人的蛋白酶处理HA蛋白的高致病性禽流感（HPAI）病毒，除了以前确定的弗林蛋白酶和前蛋白转化酶5和6。来自所有HPAI病毒H5和H7株的HA具有两个切割位点基序之一，在bar -X-K/R-R基序下的（R），在位置P4的bar下具有（R），以及在bar -K/R-K/T-R基序下的（K），在位置P4的bar下具有（K）。在具有这些切割位点基序的合成14-残基HPAI病毒HA肽的研究中，弗林蛋白酶在钙存在下仅优先切割具有bar -K-K-R基序下的（R）的HA肽，而不切割具有其它基序的肽，而MSPL和TMPRSS 13在钙不存在下有效切割两种类型的HA肽（具有bar下的（R）/bar -K-K-R基序下的（K）的那些）。全长重组HPAI病毒HA与（K）下bar -K-K-R切割基序表现出不良的敏感性切割的MSPL或TMPRSS 13和弗林蛋白酶的存在下，在感染的细胞中，但它被转化为成熟的HA亚基表达MSPL或TMPRSS 13，与膜融合的巨细胞形成。这种转化和膜融合被MSPL和TMPRSS 13的抑制剂抑制。此外，仅在表达MSPL和TMPRSS 13的细胞中检测到具有bar -K-K-R切割位点基序下的（K）的遗传修饰的活HPAI病毒A/Crow/京都/53/2004（H5 N1）的感染和增殖。
Host cellular proteases induce influenza virus entry into cells by cleaving the viral surface envelope glycoprotein hemagglutinin (HA). However, details on the cellular proteases involved in this event are not fully available. We report here that ubiquitous type II transmembrane serine proteases, MSPL and its splice variant TMPRSS13, are novel candidates for proteases processing HA proteins of highly pathogenic avian influenza (HPAI) viruses, apart from the previously identified furin and proprotein convertases 5 and 6. HAs from all HPAI virus H5 and H7 strains have one of two cleavage site motifs, the (R) under bar -X-K/R-R motif with (R) under bar at position P4 and the (K) under bar -K/R-K/T-R motif with (K) under bar at position P4. In studies of synthetic 14-residue HPAI virus HA peptides with these cleavage site motifs, furin preferentially cleaved only HA peptides with the (R) under bar -K-K-R motif in the presence of calcium and not peptides with the other motif, whereas MSPL and TMPRSS13 cleaved both types of HA peptides (those with the (R) under bar/(K) under bar -K-K-R motif) efficiently in the absence of calcium. Full-length recombinant HPAI virus HA with the (K) under bar -K-K-R cleavage motif exhibited poor susceptibility to cleavage in the absence of MSPL or TMPRSS13 and the presence of furin in infected cells, but it was converted to mature HA subunits in transfected cells expressing MSPL or TMPRSS13, with membrane-fused giant-cell formation. This conversion and membrane fusion were suppressed by inhibitors of MSPL and TMPRSS13. Furthermore, infection with and multiplication of genetically modified live HPAI virus A/Crow/Kyoto/53/2004 (H5N1) with the (K) under bar -K-K-R cleavage site motif were detected only in MSPL-and TMPRSS13-expressing cells.