细胞蛋白质稳定中的菌细菌沙佩罗宁:证据表明Cpn60.1和Cpn60.2介导的蛋白质折叠的沙佩龙功能
Bakul Piplani1, C M Santosh Kumar2,3, Peter A Lund2,3
1Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, India.
Molecular microbiology
|June 23, 2023
概括
结核菌的伴侣素MtbCpn60.1和MtbCpn60.2有助于蛋白质折叠. MtbCpn60.2比MtbCpn60.1更有效地支持GroEL枯竭的大肠杆菌的细胞存活和分裂.
科学领域:
- 分子生物学分子生物学
- 微生物学 微生物学
- 蛋白质的生物化学 蛋白质的生物化学
背景情况:
- 结核菌菌有两种伴侣素,MtbCpn60.1和MtbCpn60.2,类似于大肠杆菌GroEL.
- 与GroEL不同,MtbCpn60蛋白质存在于较低阶的寡合体中.
- 在此之前,MtbCpn60.1的功能是未知的,而MtbCpn60.2可以取代GroEL.
研究的目的:
- 为了研究MtbCpn60.1和MtbCpn60.2.2.的分子伴侣功能.
- 为了比较它们在GroEL缺陷的大肠杆菌模型中协助折叠必需蛋白质的能力.
- 阐明这两种M.结核病伴侣的不同角色和客户特点.
主要方法:
- 使用GroEL枯竭的大肠杆菌菌株来评估MtbCpn60.1和MtbCpn60.2的功能.
- 测试了陪护人的能力,以支持义务陪护人客户的折叠:Dapa,FtsE和MetK.
- 评估细胞存活,分裂,生长和增殖作为沙佩罗宁活动的指标.
主要成果:
- 通过帮助DapA和FtsE折叠,MtbCpn60.1和MtbCpn60.2都支持细胞存活和分裂.
- MtbCpn60.2显示了GroEL枯竭的大肠杆菌的完整救援,而MtbCpn60.1显示了有限的救援.
- 与MtbCpn60.2相比,MtbCpn60.1表现出支持细胞生长和MetK折叠的能力有限.
结论:
- MtbCpn60.1和MtbCpn60.2具有不同的分子伴侣活动和客户端特征.
- MtbCpn60.2与GroEL的功能重叠比MtbCpn60.1.1更广泛.
- 热稳定性,效率,客体和动作模式的差异可能源于内在的序列特征.
相关概念视频
Bacterial Protein Maturation
40
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...
40
Molecular Chaperones and Protein Folding
18.1K
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
The...
18.1K
Cotranslational Protein Translocation
7.4K
Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
7.4K
Post-translational Translocation of Proteins to the RER
5.8K
A sizable fraction of proteins destined for ER are first synthesized in the cell cytosol and then transported across the ER membrane–a process called post-translational translocation. Similar to cotranslationally translocated proteins, these proteins also use the Sec translocon complex to enter the ER lumen.
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
5.8K
The Spindle Assembly Checkpoint
3.2K
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
3.2K
Protein Folding Quality Check in the RER
3.8K
ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm...
3.8K


