Related Experiment Video

Updated: Jul 4, 2026

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay
12:26

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

Published on: May 3, 2018

Essential function of TORC2 in PKC and Akt turn motif phosphorylation, maturation and signalling

Tsuneo Ikenoue1, Ken Inoki, Qian Yang

  • 1Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.

The EMBO Journal
|June 21, 2008
PubMed

Insights

Mammalian target of rapamycin complex 2 (mTORC2) phosphorylates key motifs in Protein Kinase C (PKC) and Akt. This mTORC2-dependent phosphorylation is crucial for PKCalpha maturation, stability, and signaling, revealing a new regulatory role.

Area of Science:

  • Cellular Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Protein Kinase C (PKC) regulates vital cellular processes including proliferation, differentiation, and apoptosis.
  • Phosphorylation of the turn motif (TM) and hydrophobic motif (HM) is critical for PKC activity.
  • The mammalian target of rapamycin complex 2 (mTORC2) is a key regulator of cell growth and survival.

Purpose of the Study:

  • To investigate the role of mTORC2 in the phosphorylation of TM and HM in conventional and novel PKCs, as well as Akt.
  • To determine the functional significance of mTORC2-dependent phosphorylation for PKCalpha maturation, stability, and signaling.

Main Methods:

  • Utilized genetic ablation of mTORC2 components (Rictor, Sin1, mTOR) in cellular models.
  • Assessed phosphorylation status of TM and HM in PKC isoforms and Akt using biochemical assays.
  • Evaluated the impact of mTORC2 ablation on PKCalpha maturation, stability, and signaling pathways.

Main Results:

  • Ablation of mTORC2 components abolished TM phosphorylation in PKCalpha and Akt, and HM phosphorylation in Akt.
  • Decreased HM phosphorylation in PKCalpha was observed upon mTORC2 component ablation.
  • mTORC2-dependent TM phosphorylation was found to be essential for PKCalpha maturation, stability, and signaling.

Conclusions:

  • mTORC2 plays a significant role in the post-translational modification of PKC by facilitating TM and HM phosphorylation.
  • This study uncovers a novel function of mTORC2 in cellular regulation through its involvement in PKC processing.
  • The findings highlight a critical link between mTORC2 and the proper functioning of the PKC signaling pathway.

More Related Videos

Assaying Protein Kinase Activity with Radiolabeled ATP08:05

Assaying Protein Kinase Activity with Radiolabeled ATP

Published on: May 26, 2017

Identification of Kinase-substrate Pairs Using High Throughput Screening11:13

Identification of Kinase-substrate Pairs Using High Throughput Screening

Published on: August 29, 2015

Related Concept Videos

PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
Calmodulin-dependent Signaling01:16

Calmodulin-dependent Signaling

Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
cAMP-dependent Protein Kinase Pathways01:25

cAMP-dependent Protein Kinase Pathways

Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...