Search results for "DNAJ"

2020

Hsp70 proteins and their Hsp40 co-chaperones are essential components of cellular chaperone networks in both prokaryotes and eukaryotes. Here, we performed a genetic analysis to define the protein domains required for the key functions of the major Hsp40/DnaJ protein Sll0897 of the cyanobacterium Synechocystis sp. PCC6803. The expression of the N-terminally located J- and G/F-domains is essential and sufficient for the proteins' fundamental in vivo functions, whereas the presence of the full-length protein, containing the C-terminal substrate-binding domains, is crucial under stress conditions.

Human pathology in NCL

2013

AbstractIn childhood the neuronal ceroid lipofuscinoses (NCL) are the most frequent lysosomal diseases and the most frequent neurodegenerative diseases but, in adulthood, they represent a small fraction among the neurodegenerative diseases. Their morphology is marked by: (i) loss of neurons, foremost in the cerebral and cerebellar cortices resulting in cerebral and cerebellar atrophy; (ii) an almost ubiquitous accumulation of lipopigments in nerve cells, but also in extracerebral tissues. Loss of cortical neurons is selective, indiscriminate depletion in early childhood forms occurring only at an advanced stage, whereas loss of neurons in subcortical grey-matter regions has not been quantit…

Induction of Mitochondrial Changes Associated with Oxidative Stress on Very Long Chain Fatty Acids (C22:0, C24:0, or C26:0)-Treated Human Neuronal Ce…

2012

In Alzheimer's disease, lipid alterations point towards peroxisomal dysfunctions. Indeed, a cortical accumulation of saturated very long chain fatty acids (VLCFAs: C22:0, C24:0, C26:0), substrates for peroxisomalβ-oxidation, has been found in Alzheimer patients. This study was realized to investigate the effects of VLCFAs at the mitochondrial level since mitochondrial dysfunctions play crucial roles in neurodegeneration. On human neuronal SK-NB-E cells treated with C22:0, C24:0, or C26:0 (0.1–20 μM; 48 h), an inhibition of cell growth and mitochondrial dysfunctions were observed by cell counting with trypan blue, MTT assay, and measurement of mitochondrial transmembrane potential (Δψm) with…

PON3 is upregulated in cancer tissues and protects against mitochondrial superoxide-mediated cell death

2012

To achieve malignancy, cancer cells convert numerous signaling pathways, with evasion from cell death being a characteristic hallmark. The cell death machinery represents an anti-cancer target demanding constant identification of tumor-specific signaling molecules. Control of mitochondrial radical formation, particularly superoxide interconnects cell death signals with appropriate mechanistic execution. Superoxide is potentially damaging, but also triggers mitochondrial cytochrome c release. While paraoxonase (PON) enzymes are known to protect against cardiovascular diseases, recent data revealed that PON2 attenuated mitochondrial radical formation and execution of cell death. Another famil…

Tumor suppression inDrosophila is causally related to the function of thelethal(2)tumorous imaginal discs gene, adnaJ homolog

1995

The Drosophila melanogaster tumor suppressor gene lethal(2)tumorous imaginal discs (l(2)tid) causes in homozygotes malignant growth of cells of the imaginal discs and the death of the mutant larvae at the time of puparium formation. We describe the molecular cloning of the l(2)tid+ gene and its temporal expression pattern in the wild-type and mutant alleles. Germ line rescue of the tumor phenotype was achieved with a 7.0 kb Hindlll-fragment derived from the polytene chromosome band 59F5. The l(2)tid+ gene spans approximately 2.5 kb of genomic DNA. The protein coding region, 1,696 bps long, is divided by an intron into two exons. The predicted Tid56 protein contains 518 amino acids and posse…

Endoplasmic Reticulum Chaperones in Viral Infection: Therapeutic Perspectives

2021

SUMMARY Viruses are intracellular parasites that subvert the functions of their host cells to accomplish their infection cycle. The endoplasmic reticulum (ER)-residing chaperone proteins are central for the achievement of different steps of the viral cycle, from entry and replication to assembly and exit. The most abundant ER chaperones are GRP78 (78-kDa glucose-regulated protein), GRP94 (94-kDa glucose-regulated protein), the carbohydrate or lectin-like chaperones calnexin (CNX) and calreticulin (CRT), the protein disulfide isomerases (PDIs), and the DNAJ chaperones. This review will focus on the pleiotropic roles of ER chaperones during viral infection. We will cover their essential role …

Specific and promiscuous functions of multiple DnaJ proteins in Synechocystis sp. PCC 6803

2011

Cyanobacterial genomes typically encode multiple Hsp70 (DnaK) and Hsp40 (DnaJ) chaperones, and in the genome of the cyanobacteriumSynechocystisPCC 6803, three DnaK proteins are encoded together with seven DnaJ proteins. While only two of the DnaJ proteins can complement the growth defect of anEscherichia coliΔdnaJstrain, only disruption of thednaJgenesll0897resulted in a growth defect at elevated temperatures. Based on the domain structure and the phenotype observed following disruption of the encoding gene, Sll0897 can be classified as a canonical heat-shock protein inSynechocystis. Furthermore, mostdnaJgenes could be deleted individually, whereas disruption of the gene encoding the DnaJ S…

The role of mitochondrial oxidative stress in aging.

2003

Mitochondria are both a major source of oxidants and a target for their damaging effects, and, therefore, mitochondrial oxidative stress appears to be a cause, rather than a consequence, of cell aging. Oxidative damage in aging is particularly high in specific molecular targets, such as mitochondrial DNA and aconitase, and mitochondrial oxidative stress may drive tissue aging through intrinsic apoptosis. Mitochondrial function and morphology are impaired upon aging, as judged by a decline in membrane potential as well as by an increase in peroxide production and size of the organelles. In view of the age-related decreases in mitochondrial protein synthesis, mitochondrial transcripts, and ex…

Espectro clínico y genético de las neuropatías hereditarias motoras distales en la Comunidad Valenciana

2022

Las neuropatías hereditarias motoras distales (NHMd) son enfermedades neuromusculares de origen genético que se caracterizan por una degeneración de la parte motora de los nervios periféricos. Se engloban dentro de un grupo más amplio de neuropatías hereditarias llamadas neuropatías tipo Charcot- Marie-Tooth (CMT). Son enfermedades que afectan a gente joven y producen una discapacidad importante. Actualmente no disponemos de tratamiento que modifique el curso de las NHMd, por lo que los esfuerzos en investigación en este grupo de enfermedades son muy importantes. El diagnóstico y el estudio de la historia natural de las diferentes formas de NHMd es complicado porque son enfermedades poco fr…