Related Experiment Video

Updated: Aug 7, 2026

Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes
15:43

Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes

Published on: January 7, 2013

Functional expression cloning reveals a central role for the receptor for activated protein kinase C 1 (RACK1) in T

Mirna Mourtada-Maarabouni1, Lucy Kirkham, Farzin Farzaneh

  • 1School of Life Sciences, Keele University, Keele, ST5 5BG, UK. bia19@biol.keele.ac.uk

Journal of Leukocyte Biology
|May 5, 2005
PubMed

Insights

This study identifies the receptor for activated protein kinase C 1 (RACK1) as a key regulator of apoptosis in T cells. Increased RACK1 expression confers resistance to various apoptotic stimuli, highlighting its critical role in cell survival pathways.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Immunology

Background:

  • Apoptosis, or programmed cell death, is crucial for T cell development and function.
  • Identifying genes that regulate apoptosis is essential for understanding T cell homeostasis and disease.
  • Previous studies have not fully elucidated the role of RACK1 in T cell apoptosis.

Purpose of the Study:

  • To identify novel genes regulating apoptosis in mammalian cells.
  • To investigate the specific role of the receptor for activated protein kinase C 1 (RACK1) in T cell apoptosis.

Main Methods:

  • Mammalian cDNA expression cloning and functional screening.
  • Selection for resistance to phytohemagglutinin and gamma-irradiation.
  • RNA interference for RACK1 down-regulation.
  • Overexpression of full-length RACK1 in T cell lines.

Main Results:

  • A partial cDNA for RACK1 was identified through a functional screen.
  • Expression of RACK1 in T cells conferred resistance to dexamethasone- and ultraviolet-induced apoptosis.
  • Down-regulation of RACK1 abolished this apoptotic resistance.
  • Overexpression of full-length RACK1 suppressed apoptosis mediated by multiple stimuli.

Conclusions:

  • RACK1 plays a significant role in the intracellular signaling pathways governing apoptosis in T cells.
  • RACK1 acts as a suppressor of apoptosis, contributing to T cell survival.
  • These findings provide new insights into the molecular mechanisms controlling T cell death and survival.

More Related Videos

Study of Protein-protein Interactions in Autophagy Research14:08

Study of Protein-protein Interactions in Autophagy Research

Published on: September 9, 2017

Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes09:40

Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes

Published on: September 28, 2018

Related Concept Videos

Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR activation may...
The Extrinsic Apoptotic Pathway01:17

The Extrinsic Apoptotic Pathway

The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
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...
Receptor Tyrosine Kinases01:26

Receptor Tyrosine Kinases

Receptor tyrosine kinases or RTKs are membrane-bound receptors that phosphorylate specific tyrosine on protein substrates. RTKs regulate cellular growth, differentiation, survival, and migration. They contain an extracellular ligand binding domain, a transmembrane domain, and a cytosolic tail with intrinsic kinase activity. Several extracellular signaling molecules activate RTKs in one or more ways and relay the signal downstream. Ligands such as platelet-derived growth factor (PDGF) or...
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...