中文摘要：

牙龈卟啉单胞菌第Ⅸ型分泌系统（T9SS）是新近发现的一种新型蛋白分泌系统,又被称为Por分泌系统（PorSS）。与以往发现的8个蛋白分泌系统不同,T9SS系统是一个仅存在于拟杆菌中的多蛋白复合体,其分泌的蛋白质N端均具有Sec依赖的Ⅰ型信号肽,C端均含有保守结构域（CTD）。牙龈卟啉单胞菌T9SS包括了内膜、外膜、细胞质以及细胞周质等重要组成部分的蛋白质,至少包括34种包含CTD的蛋白,这些蛋白参与调控的相关毒力因子包括牙龈素、菌毛、脂多糖、HBP35、CPG70蛋白和蛋白质-肽基精氨酸脱亚氨酶等。这些包含CTD的毒力蛋白通过T9SS转定位在细胞外膜上,然后释放至胞外,从而对牙周组织起破坏作用。本文对牙龈卟啉单胞菌T9SS的研究进展作一综述,以便于深入理解该菌的毒力机制。

英文摘要：

In recent years, the study found that Porphyromonas gingivalis type Ⅸ secretion system （T9SS） is a novel protein secretion system, also known as Por secretion system （PorSS）. Unlike the eight protein secretion systems found in the past, the system is a polyprotein complex found only in Bacteroides. The secreted proteins have both N- and C-terminus, where the former includes Sec-dependent typeⅠsignals peptide, and the latter contains conserved domains （C-terminal conserved domain, CTD）. Porphyromonas gingivalis T9SS includes proteins such as intima, outer membrane, cytoplasm, and cell cycle, including at least 34 proteins containing CTD. Porphyromonas gingivalis T9SS is involved in regulating associated virulence factors including gingivin, fimbriae, lipopolysaccharide, HBP35, CPG70 protein and peptidyl-arginine deiminase. These CTD-containing virulence proteins are localized by T9SS and then released to the extracellular domain, thereby destroying periodontal tissue. Therefore, this review summarizes the research progress on the T9SS of Porphyromonas gingivalis.