Diverse nature of ClpX degradation motifs in Streptococcus mutans.
Diverse nature of ClpX degradation motifs in Streptococcus mutans.
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DOI：
10.1128/spectrum.03457-23
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发表时间：
2024-01-11
影响因子：
3.7
通讯作者：
Biswas, Indranil
中科院分区：
文献类型：
--
作者：
Gurung, Vivek;Biswas, Saswati;Biswas, Indranil
蛋白质稳态是一个重要的过程，它依赖于参与正确蛋白质折叠的不同蛋白质的协同努力，通过将错误折叠的蛋白质重折叠成其正确构象或降解错误折叠的蛋白质来决定错误折叠的蛋白质的命运。在革兰氏阳性细菌中，AAA+ ATP酶如ClpX、ClpC和ClpE与蛋白水解ClpP相互作用并降解错误折叠的蛋白质。Clp ATP酶还根据细胞需要维持不同蛋白质的量。在链球菌中，这些Clp ATP酶在各种生理过程中起着至关重要的作用，这些生理过程有助于毒力、细胞生长和分裂、胁迫耐受性、感受态发育和生物膜形成。在低G + C革兰氏阳性菌中存在的Clp ATP酶复合物中，ClpX/P是主要的蛋白水解系统。与在大肠杆菌和其他细菌中鉴定的许多ClpX/P底物相反，对链球菌中ClpX/P底物的身份知之甚少。使用后期对数生长条件下的蛋白质组学方法，我们筛选了可能被ClpX/P降解的推定底物;通过其他方法鉴定并验证了几种潜在底物。SpxA 2就是这样一个候选蛋白，通过Western blot，我们证实它确实识别SpxA 2。我们进一步鉴定了位于SpxA 2的C-末端的Ala-Ala-Leu作为ClpX/P降解信号。使用绿色荧光蛋白报告系统，我们进一步证实了几个ClpX/P降解信号。此外，我们发现ClpX的锌结合结构域是底物识别所必需的。我们的体外数据表明，衔接子或其他辅助因子可能需要ClpX/P介导的底物识别或降解。需要进一步的研究来确定细胞中这些因子的身份。细胞质Clp相关蛋白酶在维持细菌细胞蛋白质组中起主要作用。ClpX/P是一种这样的蛋白水解复合物，其对于保持蛋白质稳态是重要的。在这项研究中，我们研究了ClpX/P在变形链球菌，一种重要的口腔病原体中的作用。我们确定了几种假定的底物，其细胞水平由S中ClpX/P调节。变异，随后发现了几个识别基序，这是关键的降解。我们的研究是第一次全面分析确定ClpX/P基序的链球菌。我们相信，确定由ClpX/P调节的底物将增强我们对这一重要病原体组的毒力调节的理解。
Protein homeostasis is an essential process that depends on concerted effort of different proteins involved in proper protein folding, deciding the fate of misfolded proteins by either refolding them into their proper conformation or degrading the misfolded proteins. In Gram-positive bacteria, AAA+ ATPases such as ClpX, ClpC, and ClpE interact with the proteolytic ClpP and degrade misfolded proteins. Clp ATPases also maintain amounts of different proteins based on the cellular need. In streptococci, these Clp ATPases play a crucial role in various physiological processes that contribute to virulence, cell growth and division, stress tolerance, competence development, and biofilm formation. Among the Clp ATPase complexes present in low G + C Gram-positive bacteria, ClpX/P is the major proteolytic system. In contrast to numerous ClpX/P substrates identified in Escherichia coli and other bacteria, very little is known about the identity of the ClpX/P substrates in streptococci. Using a proteomic approach under late logarithmic growth condition, we screened for putative substrates that might be degraded by ClpX/P; several potential substrates were identified and verified by other methods. SpxA2 is one such candidate protein, and by Western blot, we confirmed that it indeed recognizes SpxA2. We further identified Ala-Ala-Leu, located at the C-terminal of SpxA2, as a ClpX/P degradation signal. Using a green fluorescent protein reporter system, we further confirmed several ClpX/P degradation signals. Furthermore, we found that the zinc-binding domain of ClpX is needed for substrate recognition. Our in vitro data indicate that the adaptor or other accessory factors might be needed for the ClpX/P-mediated substrate recognition or degradation. Additional investigations are needed to determine the identity of these factors in the cell. Cytoplasmic Clp-related proteases play a major role in maintaining cellular proteome in bacteria. ClpX/P is one such proteolytic complex that is important for conserving protein homeostasis. In this study, we investigated the role of ClpX/P in Streptococcus mutans, an important oral pathogen. We identified several putative substrates whose cellular levels are regulated by ClpX/P in S. mutans and subsequently discovered several recognition motifs that are critical for degradation. Our study is the first comprehensive analysis of determining ClpX/P motifs in streptococci. We believe that identifying the substrates that are regulated by ClpX/P will enhance our understanding about virulence regulation in this important group of pathogens.
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DOI：
10.1016/j.bbamcr.2011.06.007
发表时间：
2012-01
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Baker TA;Sauer RT
通讯作者：
Sauer RT
影响因子：
--
作者：
Green R;Rogers EJ
通讯作者：
Rogers EJ
影响因子：
3.7
作者：
Biswas, Saswati;Keightley, Andrew;Biswas, Indranil
通讯作者：
Biswas, Indranil
影响因子：
16
作者：
Flynn, JM;Neher, SB;Baker, TA
通讯作者：
Baker, TA
DOI：
10.1093/bioinformatics/bts520
发表时间：
2012-11-01
期刊：
Bioinformatics (Oxford, England)
影响因子：
--
作者：
R RK;N S N;S P A;Sinha D;Veedin Rajan VB;Esthaki VK;D'Silva P
通讯作者：
D'Silva P