Related Experiment Video

Updated: Oct 3, 2026

Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development
09:32

Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development

Published on: June 15, 2017

Pasteurella multocida toxin: the mitogenic toxin that stimulates signalling cascades to regulate growth and

A J Lax1, A E Grigoriadis

  • 1Department of Oral Microbiology, Guy's King's and St Thomas' Dental Institute, King's College London, UK. alistair.lax@kcl.ac.uk

International Journal of Medical Microbiology : IJMM
|October 30, 2001
PubMed

Insights

Pasteurella multocida toxin (PMT) activates multiple cell signaling pathways, impacting cell growth and differentiation. This toxin inhibits bone cell differentiation, contributing to bone resorption in porcine diseases.

Area of Science:

  • Microbiology
  • Cell Biology
  • Toxicology

Background:

  • Pasteurella multocida toxin (PMT) is a potent mitogen.
  • PMT activates intracellular signaling cascades, including Gq and Rho pathways.
  • The toxin's precise intracellular target remains unidentified.

Purpose of the Study:

  • To elucidate the signaling pathways affected by PMT.
  • To investigate PMT's role in cellular differentiation, particularly in bone cells.
  • To understand the mechanisms underlying PMT-induced porcine diseases.

Main Methods:

  • Analysis of intracellular signaling pathways (Gq, Rho, Ras-MAP kinase).
  • Assessment of phospholipase C, protein kinase C, and intracellular calcium levels.
  • In vitro studies on bone cell differentiation and mineralized nodule formation.

Main Results:

  • PMT activates Gq and Rho proteins, leading to increased phospholipase C, protein kinase C, and intracellular calcium.
  • Rho activation results in cytoskeletal reorganisation and focal adhesion kinase phosphorylation.
  • PMT inhibits bone cell differentiation, preventing mineralized bone nodule formation.

Conclusions:

  • PMT profoundly perturbs host cell signal transduction pathways.
  • The toxin's effects on cell signaling contribute to its mitogenic and differentiation-inhibiting activities.
  • PMT is implicated in bone resorption observed in porcine diseases.

More Related Videos

Intracellular Phosphoflow Cytometry of Acute Myeloid Leukemia Patient-Derived Xenotransplants07:38

Intracellular Phosphoflow Cytometry of Acute Myeloid Leukemia Patient-Derived Xenotransplants

Published on: June 6, 2025

Related Concept Videos

Mitogens and the Cell Cycle02:38

Mitogens and the Cell Cycle

Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...
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...
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...
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...
The Ras Gene02:38

The Ras Gene

The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...