Upregulation of cytosolic chaperonin CCT subunits during recovery from chemical stress that causes accumulation of unfolded proteins.
ABSTRACT The chaperonin containing TCP-1 (CCT) is a molecular chaperone consisting of eight subunit species and assists in the folding of actin, tubulin and some other cytosolic proteins. We examined the stress response of CCT subunit proteins in mammalian cultured cells using chemical stressors that cause accumulation of unfolded proteins. Levels of CCT subunit proteins in HeLa cells were coordinately and transiently upregulated under continuous chemical stress with sodium arsenite. CCT subunit levels in several mammalian cell lines were also upregulated during recovery from chemical stress caused by sodium arsenite or a proline analogue, L-azetidine-2-carboxylic acid. Several unidentified proteins that were newly synthesized and associated with CCT were found to increase concomitantly with CCT subunits themselves and known substrates during recovery from the stress. These results suggest that CCT plays important roles in the recovery of cells from protein damage by assisting in the folding of proteins that are actively synthesized and/or renatured during this period.
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- "As a hetero-oligomeric chaperonin consisting of eight or nine different subunits, chaperonin CCT possess several highly conserved motifs for ATP binding despite showing only approximately 30 % amino acid homology with each subunit (Chagoyen et al. 2014). Thus, as a rule of thumb, both common ATPase function and subunitspecific function are considered to co-exist in each subunit (Yokota et al. 2000b). Similar to other chaperonins, all CCT subunits are approximately 60 kDa and are arranged into a hexadecamer complex, forming a stacked multimeric ring with a central cavity (Muñoz et al. 2011). "
ABSTRACT: Chaperonin containing the T-complex polypeptide-1 (CCT), which is known to be involved in intracellular assembly and folding of proteins, is a class of chaperonin omnipresent in all forms of life. Previous studies showed that CCT played a vital role in cold hardiness of various animals. In order to understand the response of the polypeptide complex to low temperature challenge and other environmental stresses, a subunit of CCT (CCTα) was cloned from the mud crab Scylla paramamosain by expressed sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE). The full-length cDNA SpCCTα was of 1972 bp and contained a 1668 bp open reading frame (ORF) encoding a polypeptide of 555 amino acids with four conserved motifs. The messenger ribonucleic acid (mRNA) levels of SpCCTα in ten tissues of adult S. paramamosain was subsequently examined and the highest expression was found in muscle, followed by gill, hepatopancreas, thoracic ganglion, hemocyte, heart, cerebral ganglion, stomach, eyestalk ganglion, and epidermis. The expressions of SpCCTα in the muscle of sub-adult crabs (pre-acclimated to 28 °C) subjected to the challenges of both lower temperatures (25, 20, 15, and 10 °C) alone and low temperatures (15 and 10 °C) in combination with salinity of 35 and 10 were further investigated by fluorescent quantitative real-time PCR (qPCR). It was revealed that when exposed to lower temperatures alone, the mRNA transcripts of the SpCCTα gene in the muscle were generally induced for significant higher expression at 10 °C treatment than the 25, 20, and 15 °C treatments; meanwhile, exposure to 15 °C also frequently led to significantly higher expression than those at 20 and 25 °C. This finding indicated that the up-regulation of SpCCTα was closely related to the cold hardiness of S. paramamosain. The results of an additional experiment challenging the sub-adult crabs with various combinations of low temperatures with different salinity conditions generally demonstrated that at both 10 and 15 °C, the expression of SpCCTα under the high salinity of 35 was significantly lower than that at low salinity of 10, implying that the damages caused by low temperatures with high salinity were less than that under low salinity.Cell Stress and Chaperones 06/2015; 20(5). DOI:10.1007/s12192-015-0612-1 · 3.16 Impact Factor
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- "Indeed, these chaperones are required for the stability and activity of a range of client proteins playing a critical role in signal transduction, cellular trafficking, chromatin remodeling, cell growth, differentiation, and apoptosis . Furthermore, the expression changes measured for Hsp90, 14-3-3 and T-complex proteins easily associate with an apoptosis reduction [19,20,21,22,23,24,25], and the anti-apoptotic role of perthamide C is also confirmed by the level alteration of other proteins, as annexin 5, dihydropyrimidinase-related protein 2 and gelsolin, independent from the folding process but in any case implicated in the apoptosis regulation [26,27,28]. "
ABSTRACT: Secondary metabolites contained in marine organisms disclose diverse pharmacological activities, due to their intrinsic ability to recognize bio-macromolecules, which alter their expression and modulate their function. Thus, the identification of the cellular pathways affected by marine natural products is crucial to provide important functional information concerning their mechanism of action at the molecular level. Perthamide C, a marine sponge metabolite isolated from the polar extracts of Theonella swinhoei and endowed with a broad and interesting anti-inflammatory profile, was found in a previous study to specifically interact with heat shock protein-90 and glucose regulated protein-94, also disclosing the ability to reduce cisplatin-mediated apoptosis. In this paper, we evaluated the effect of this compound on the whole proteome of murine macrophages cells by two-dimensional DIGE proteomics. Thirty-three spots were found to be altered in expression by at least 1.6-fold and 29 proteins were identified by LC ESI-Q/TOF-MS. These proteins are involved in different processes, such as metabolism, structural stability, protein folding assistance and gene expression. Among them, perthamide C modulates the expression of several chaperones implicated in the folding of proteins correlated to apoptosis, such as Hsp90 and T-complexes, and in this context our data shed more light on the cellular effects and pathways altered by this marine cyclo-peptide.Marine Drugs 04/2013; 11(4):1288-99. DOI:10.3390/md11041288 · 2.85 Impact Factor
Aquatic Toxicology 02/2011; · 3.45 Impact Factor
- "Chaperonin containing TCP1 (CCT) is a member of the group II chaperonins, and has an important function in maintaining cellular homeostasis by assisting the folding of many important proteins (Spiess et al., 2004; Won et al., 1998). CCT subunit levels are reported to up-regulate in several mammalian cell lines during recovery from chemical stress (Yokota et al., 2000), suggesting that they respond to protein damage and play a role in recovery of the cells from stress. Thus, the affected protein modification could be evidence of an accumulation of abnormal proteins (e.g. "