Proteostasis is critical for the maintenance of life. In neuronal cells an imbalance between protein synthesis and degradation is thought to be involved in the pathogenesis of neurodegenerative diseases during aging. Partly, this seems to be due to a decrease in the activity of the ubiquitin-proteasome system, wherein the 20S/26S proteasome complexes catalyse the proteolytic step. We have characterised 20S and 26S proteasomes from cerebrum, cerebellum and hippocampus of 3 weeks old (young) and 24 month old (aged) rats. Our data reveal that the absolute amount of the proteasome is not dfferent between both age groups. Within the majority of standard proteasomes in brain the minute amounts of immuno-subunits are slightly increased in aged rat brain. While this goes along with a decrease in the activities of 20S and 26S proteasomes to hydrolyse synthetic fluorogenic tripeptide substrates from young to aged rats, the capacity of 26S proteasomes for degradation of poly-Ub-model substrates and its activation by poly-Ub-substrates is not impaired or even slightly increased in brain of aged rats. We conclude that these alterations in proteasome properties are important for maintaining proteostasis in the brain during an uncomplicated aging process.
Light is a major determinant of plant growth and survival. NONEXPRESSER OF PATHOGENESIS-RELATED GENES 1 (NPR1) acts as a receptor for salicylic acid (SA) and serves as the key regulator of SA-mediated immune responses. However, the mechanisms by which plants integrate light and SA signals in response to environmental changes, as well as the role of NPR1 in regulating plant photomorphogenesis, remain poorly understood.
Background: Kinectin 1 () is a membrane protein involved in intracellular organelle motility. However, the role of in human pan-cancer lacks systematic analysis and evaluation. The aim of this study is to evaluate the expression profile and clinical value in human cancers by performing a pan-cancer analysis of .
The Bombyx mori nucleopolyhedrovirus (BmNPV) is a DNA virus that affects the silkworm, , causing substantial economic losses in sericulture. This study investigates the mechanisms underlying budded virus egress, focusing on the roles of the ubiquitin-proteasome pathway (UPP) machinery. BmNPV produces two virion types: budded virions (BVs) and occlusion-derived virions (ODVs), which differ in their envelope origins and functions.
Background: The 26S non-ATPase regulatory subunit 11 () is a multiprotein complex that participates in the ATP-dependent degradation of ubiquitinated proteins and is essential to the regulation of embryonic stem cell proteasome activity. has been demonstrated to be a factor contributing to the emergence and progression of cancer cells. However, the prognostic value and potential biological function of in lung adenocarcinoma (LUAD) remains unclear.
DNA-protein crosslinks (DPCs) are endogenous and chemotherapy-induced genotoxic DNA lesions and, if not repaired, lead to embryonic lethality, neurodegeneration, premature ageing, and cancer. DPCs are heavily polyubiquitinated, and the SPRTN protease and 26S proteasome emerged as two central enzymes for DPC proteolysis. The proteasome recognises its substrates by their ubiquitination status.
