Key Laboratory of Zoonotic of Liaoning Province, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China.
Front Cell Infect Microbiol. 2021 Jan 8;10:603457. doi: 10.3389/fcimb.2020.603457. eCollection 2020.
In spp., the type IV secretion system (T4SS) is essential for bacterial intracellular survival and inhibition of the host innate immune response. The T4SS secretes 15 different effectors to escape host immunity and promote intracellular replication. Among them, BspF has a GNAT-family acetyltransferase domain, implying its acetyltransferase activity. We confirmed that BspF has acetyltransferase activity (data not shown) and de-crotonyltransferase activity. However, BspF overexpressed in HEK-293T cells can also enhance octamer crotonylation . Then we enriched crotonylated proteins and conducted LC-MS to study the crotonylation changes of proteins in HEK-293T cells caused by BspF overexpression. A total of 5,559 crotonylation sites were identified on 1,525 different proteins, of which 331 sites on 265 proteins were significantly changed. We found that Rab9A and RAP1B in proteomics data have a great impact on survival, so we speculate that BspF may influence the function of host proteins by altering crotonylation, thereby promoting the intracellular propagation of .
在 spp. 中，IV 型分泌系统（T4SS）对于细菌的细胞内生存和抑制宿主固有免疫反应至关重要。该 T4SS 分泌 15 种不同的效应物以逃避宿主免疫并促进细胞内复制。其中，BspF 具有 GNAT 家族乙酰转移酶结构域，暗示其具有乙酰转移酶活性。我们证实 BspF 具有乙酰转移酶活性（未显示数据）和去丁酰基转移酶活性。然而，在 HEK-293T 细胞中过表达的 BspF 也可以增强八聚体丁酰化。然后，我们富集了丁酰化蛋白，并进行了 LC-MS 分析，以研究 BspF 过表达对 HEK-293T 细胞中蛋白质丁酰化变化的影响。在 1525 种不同的蛋白质中鉴定出 5559 个丁酰化位点，其中 265 种蛋白质上的 331 个位点发生了显著变化。我们发现蛋白质组学数据中的 Rab9A 和 RAP1B 对生存有很大影响，因此我们推测 BspF 可能通过改变丁酰化来影响宿主蛋白的功能，从而促进的细胞内传播。
