Pluto Bioinformatics

GSE57998: Ataxin-2 modulates mRNA levels of proteins in ribosomal large and small subunit and in translation initiation complex

Bulk RNA sequencing

Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disorder, caused by an unstable CAG-repeat expansion in the SCA2 gene, which encodes a polyglutamine (polyQ) domain expansion in the protein ataxin-2 (ATXN2). The RNA-binding protein ATXN2 interacts with the poly(A)-binding protein PABPC1, localizing to ribosomes in the rough endoplasmic reticulum or in polysomes. Under cell stress ATXN2 and PABPC1 are relocated to stress granules where mRNAs are protected from translation and from degradation. It is unknown whether ATXN2 associates preferentially with specific mRNAs or how it modulates their processing. Here, we investigated the RNA profile of liver and cerebellum from adult Atxn2 knock-out (Atxn2-/-) mice, employing oligonucleotide microarrays for screening and RNA deep sequencing for validation. We consistently observed modest upregulations for the level of many mRNAs encoding proteins of the ribosomal large and small subunit as well as the translation initiation complex. Quantitative reverse transcriptase PCR in liver tissue confirmed these upregulations for the ribosomal components Rpl14, Rpl18, Rps10, Rps18, Gnb2l1, the translation initiation factors Eif2s2, Eif3s6, Pabpc1, and the ribosomal biogenesis modulator Nop10. Quantitative immunoblots substantiated the effects for PABPC1. Thus, the physiological role of ATXN2 modifies the abundance of cellular translation factors. SOURCE: Gunnar,H,Heine Saarland University Medical Center