mTOR and S6K1 drive polycystic kidney by the control of Afadin-dependent oriented cell division.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32581239.
- Also identified by DOI 10.1038/s41467-020-16978-z and PMC identifier 7314806.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
mTOR activation is essential and sufficient to cause polycystic kidneys in Tuberous Sclerosis Complex (TSC) and other genetic disorders. In disease models, a sharp increase of proliferation and cyst formation correlates with a dramatic loss of oriented cell division (OCD). We find that OCD distortion is intrinsically due to S6 kinase 1 (S6K1) activation. The concomitant loss of S6K1 in Tsc1-mutant mice restores OCD but does not decrease hyperproliferation, leading to non-cystic harmonious hyper growth of kidneys. Mass spectrometry-based phosphoproteomics for S6K1 substrates revealed Afadin, a known component of cell-cell junctions required to couple intercellular adhesions and cortical cues to spindle orientation. Afadin is directly phosphorylated by S6K1 and abnormally decorates the apical surface of Tsc1-mutant cells with E-cadherin and α-catenin. Our data reveal that S6K1 hyperactivity alters centrosome positioning in mitotic cells, affecting oriented cell division and promoting kidney cysts in conditions of mTOR hyperactivity.
Medical subject headings
- Cell Division
- Kinesins
- Mechanistic Target of Rapamycin Complex 1
- Myosins
- Polycystic Kidney Diseases
- Ribosomal Protein S6 Kinases, 90-kDa