Related Experiment Videos
Enhanced microtubule-dependent trafficking and p53 nuclear accumulation by suppression of microtubule dynamics
Paraskevi Giannakakou1, Michel Nakano, Kyriacos C Nicolaou
1Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322, USA. paraskevi_giannakakou@emory.org
Abstract:
The tumor suppressor protein p53 localizes to microtubules (MT) and, in response to DNA damage, is transported to the nucleus via the MT minus-end-directed motor protein dynein. Dynein is also responsible for MT-mediated nuclear targeting of adenovirus type 2 (Ad2). Here we show that treatment with low concentrations of MT-targeting compounds (MTCs) that do not disrupt the MT network but are known to suppress MT dynamics enhanced p53 nuclear accumulation, and the activation of the p53-downstream target genes. p53 nuclear accumulation required binding of MTCs to MTs and enhanced the induction of p53-up-regulated modulator of apoptosis (PUMA) mRNA and apoptosis on challenging cells with the DNA-damaging drug adriamycin. Low concentrations of MTCs enhanced the rate of movement of fluorescent Ad2 to the nucleus and increased the nuclear targeting efficiency of Ad2. We propose that suppression of MT dynamics by low concentrations of MTCs enhances MT-dependent trafficking toward the minus ends of MTs and facilitates nuclear targeting.
Insights
Microtubule-targeting compounds (MTCs) enhance the nuclear transport of tumor suppressor p53 and adenovirus (Ad2) by subtly suppressing microtubule dynamics. This improves the efficiency of essential cellular and viral nuclear delivery pathways.
Area of Science:
- Cell Biology
- Molecular Biology
- Virology
Background:
- The tumor suppressor protein p53 and adenovirus type 2 (Ad2) rely on microtubule (MT)-dependent transport, specifically involving the motor protein dynein, for nuclear localization.
- Microtubule dynamics play a crucial role in intracellular trafficking and organelle positioning.
Purpose of the Study:
- To investigate the effect of low concentrations of microtubule-targeting compounds (MTCs) on p53 nuclear accumulation and Ad2 nuclear targeting.
- To determine if suppressing microtubule dynamics enhances MT-dependent nuclear transport pathways.
Main Methods:
- Treatment of cells with low concentrations of MTCs that inhibit MT dynamics without disrupting the MT network.
- Assessment of p53 nuclear accumulation and activation of p53-downstream target genes (e.g., PUMA mRNA) following DNA damage.
- Tracking the nuclear transport rate and efficiency of fluorescently labeled Ad2 particles.
Main Results:
- Low-dose MTC treatment significantly enhanced p53 nuclear accumulation and the induction of PUMA mRNA and apoptosis.
- p53 nuclear accumulation was dependent on MTC binding to microtubules.
- MTCs increased the speed and efficiency of Ad2 nuclear targeting.
Conclusions:
- Suppression of microtubule dynamics by low concentrations of MTCs enhances MT-minus-end-directed trafficking.
- This enhanced trafficking facilitates the nuclear delivery of both endogenous proteins like p53 and viral particles like Ad2.
- MTCs represent a potential tool to modulate nuclear transport efficiency in cellular and viral contexts.