Dataset Information

PABPC1 SUMOylation enhances cell survival by promoting mitophagy through stabilizing U-rich mRNAs within stress granules (4sU-Seq)

ABSTRACT: Under cellular stress conditions, translationally stalled mRNAs and associated proteins coalesce into stress granules (SGs), intricately regulating gene expression. Small Ubiquitin-like Modifier (SUMO) modification plays important role in SG dynamics but its function is yet not fully understood. Here, we report that SUMOylation of Poly(A)-Binding Protein Cytoplasmic 1 (PABPC1), a pivotal SG constituent, is dynamically regulated by a variety of stress stimuli, including oxidative, heat, osmotic, and nutritional stresses, facilitating SG assembly. Crucially, we demonstrate that SUMOylation of PABPC1 stabilizes mRNAs bearing conserved U-rich elements under stress, thus preserving their stability. Notably, our study reveals that the SUMOylation of PABPC1 stabilizes transcripts critical to the mitophagy pathway, thereby enhancing mitophagy in response to stress and then contributing to the maintenance of cellular homeostasis and enhancing the tumor cell survival under adverse conditions.

ORGANISM(S): Homo sapiens

PROVIDER: GSE260508 | GEO | 2025/05/10

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Spinocerebellar Ataxia Type 2 (SCA2) is caused by expansion of a polyglutamine encoding triplet repeat in the human ATXN2 gene beyond (CAG)31. This is thought to mediate toxic gain-of-function by protein aggregation, and affect RNA processing, resulting in degenerative processes affecting preferentially cerebellar neurons. As a faithful animal model, we generated a knock-in mouse replacing the single CAG of murine Atxn2 with CAG42, a frequent patient genotype. This expansion size was inherited stably. The mice showed phenotypes with reduced weight and later motor incoordination. Although brain Atxn2 mRNA became elevated, soluble ATXN2 protein levels diminished over time, which might explain partial loss-of-function effects. Deficits in soluble ATXN2 protein correlated with the appearance of insoluble ATXN2, a progressive feature in cerebellum possibly reflecting toxic gains-of-function. Since in vitro ATXN2 overexpression was known to reduce levels of its protein interactor PABPC1, we studied expansion effects on PABPC1. In cortex, PABPC1 transcript, soluble and insoluble protein levels were increased. In more vulnerable cerebellum the progressive insolubility of PABPC1 was accompanied by decreased soluble protein levels, with PABPC1 mRNA showing no compensatory increase. The sequestration of PABPC1 into insolubility by ATXN2 function gains was validated in human cell culture. To understand consequences on mRNA processing, transcriptome profiles at medium and old age in three different tissues were studied and demonstrated selective induction of Fbxw8 in old cerebellum. Fbxw8 is encoded next to the Atxn2 locus and was shown in vitro to decrease the level of expanded insoluble ATXN2 protein. In conclusion, our data support the concept that expanded ATXN2 undergoes progressive insolubility and affects PABPC1 by a toxic gain-of-function mechanism with tissue-specific effects, which may be partially alleviated by the induction of FBXW8. Factorial design comparing Atxn2 knock-in mice with wild type littermates in three different tissues (brainstem, cerebellum, liver)

Dataset Information

PABPC1 SUMOylation enhances cell survival by promoting mitophagy through stabilizing U-rich mRNAs within stress granules (4sU-Seq)

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets