The diverse involvement of heterogeneous nuclear ribonucleoprotein K in mitochondrial response to insulin

Abstract

Heterogeneous nuclear ribonucleoprotein K (hnRNP K protein) is an RNA/DNA-binding protein that acts in several compartments, including mitochondria. It integrates cellular signaling cascades with multiple processes of gene expression mechanisms. Our studies demonstrate that: (1) insulin activates the import of hnRNP K protein into mitochondria in vitro and in vivo; (2) overexpression of hnRNP K protein modulates insulin-activated mitochondrial gene expression; and (3) insulin treatment stimulates binding of hnRNP K protein to mitochondrial DNA. Based on these and our previously reported results we conclude that hnRNP K protein may be a mediator of mitochondrial response to insulin.

Heterogeneous Nuclear Ribonucleoprotein L is required for the survival and functional integrity of murine hematopoietic stem cells

“…High-throughput sequencing (CLIP-seq) in T cells to find RNA binding sites of hnRNP L revealed a significant number of transcripts aligned to mitochondrial DNA41. Additionally, hnRNP K, another member of the family of RNA-binding proteins, has been shown to localize to the mitochondria and been co-purified with mitochondrial RNA4243. It is thus conceivable that hnRNP L is essential for transcription and/or RNA processing in the ‘powerhouse of the cell’ and its loss leads to mitochondrial dysfunction.…”

S-Guanylation Proteomics for Redox-Based Mitochondrial Signaling

“…The first protein regulates mitochondrial transcription (31) and affects mitochondrial responses to insulin (9). Vimentin modulates mitochondrial motility (28).…”

Functional diversity of the hnRNPs: past, present and perspectives

“…In this way, hnRNP K acts as a 'docking platform' to co-ordinate nucleic acid metabolism and mediate cross-talk between signalling pathways [101]. Its role in integrating cellular signals is important in several key pathways, including the p53 transcriptional response to DNA damage [102] and the mitochondrial response to insulin [103]. Thus hnRNP K is at the centre of a vast interaction network, with 114 binding partners having been identified via affinity purification coupled with MS [104].…”