La Deletion from Mouse Brain Alters Pre-tRNA Metabolism and Accumulation of Pre-5.8S rRNA, with Neuron Death and Reactive Astrocytosis.

ABSTRACT: Human La antigen (Sjögren's syndrome antigen B [SSB]) is an abundant multifunctional RNA-binding protein. In the nucleoplasm, La binds to and protects from 3' exonucleases, the ends of precursor tRNAs, and other transcripts synthesized by RNA polymerase III and facilitates their maturation, while a nucleolar isoform has been implicated in rRNA biogenesis by multiple independent lines of evidence. We showed previously that conditional La knockout (La cKO) from mouse cortex neurons results in defective tRNA processing, although the pathway(s) involved in neuronal loss thereafter was unknown. Here, we demonstrate that La is stably associated with a spliced pre-tRNA intermediate. Microscopic evidence of aberrant nuclear accumulation of 5.8S rRNA in La cKO is supported by a 10-fold increase in

SUBMITTER: Blewett NH 

PROVIDER: S-EPMC5477551 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature