hVps34 is a nutrient-regulated lipid kinase required for activation of p70 S6 kinase

Byfield MP, Murray JT, Backer JM · 2005 · J Biol Chem · Atlas ID BYF2005

What this study shows

Opens a second, non-canonical route by which amino acids reach mTORC1. The class III PI 3-kinase hVps34 is switched off by amino acid or glucose starvation and by AMPK activation, and is required for S6K1 and 4E-BP1 phosphorylation, yet it sits outside the insulin/class I PI3K input (it does not affect Akt or TSC2 phosphorylation). Boundary: cell lines and knockdown/overexpression only; the step is nutrient-regulated but the sensor itself is not identified.

Abstract

ShowHide

Mammalian cells respond to nutrient deprivation by inhibiting energy consuming processes, such as proliferation and protein synthesis, and by stimulating catabolic processes, such as autophagy. p70 S6 kinase (S6K1) plays a central role during nutritional regulation of translation. S6K1 is activated by growth factors such as insulin, and by mammalian target of rapamycin (mTOR), which is itself regulated by amino acids. The Class IA phosphatidylinositol (PI) 3-kinase plays a well recognized role in the regulation of S6K1.

Read the full abstract on PubMed →

At a glance

Evidence type	M Molecular — cells, biochemistry, structure Marked M because it is molecular or in-vitro work (model: Human and hamster cell lines (HeLa, CHO)) rather than a whole-organism health-outcome study. That is often exactly where causal biology gets established -- the code says which system the finding was shown in, and nothing about how good the work is.
Study type	5 - Mechanistic / In Vitro
Model system	Human and hamster cell lines (HeLa, CHO)
Journal	J Biol Chem
Year	2005
Peer reviewed	Yes
Record last updated	2026-09-23
Source	DOI 10.1074/jbc.M507201200 · PMID 16049009

Cite this paper

ShowHide

Byfield, M. P., Murray, J. T., & Backer, J. M. (2005). hVps34 is a nutrient-regulated lipid kinase required for activation of p70 S6 kinase. J Biol Chem. https://doi.org/10.1074/jbc.M507201200

@article{BYF2005,
  author       = {Byfield, M. P. and Murray, J. T. and Backer, J. M.},
  title        = {{hVps34 is a nutrient-regulated lipid kinase required for activation of p70 S6 kinase}},
  journal      = {J Biol Chem},
  year         = {2005},
  doi          = {10.1074/jbc.M507201200},
  note         = {PMID: 16049009},
}

Cite this Atlas record

The record is the Atlas's own work — the evidence label, the extracted findings and the links. It is cited as part of the dataset, not as the paper.

Barton, O. (2026). Oliver's mTOR Atlas (record BYF2005) [Data set]. https://mtor-atlas.org/study/BYF2005/ · Dataset DOI 10.5281/zenodo.22059963

@misc{atlas_BYF2005,
  author       = {Barton, Oliver},
  title        = {{Oliver's mTOR Atlas}, record BYF2005},
  howpublished = {Data set},
  year         = {2026},
  url          = {https://mtor-atlas.org/study/BYF2005/},
  doi          = {10.5281/zenodo.22059963}
}