Phospholipid signaling during stramenopile development

Area of Science:

• Plant and animal cell biology
• Marine biology
• Biochemistry

Background:

• Sessile organisms require complex signaling for environmental adaptation.
• Phospholipid signaling pathways, including Phospholipase D (PLD) and Phospholipase C (PLC), are crucial for cellular modifications.
• These pathways produce phosphatidic acid (PA), a signaling molecule that regulates microtubules (MTs), F-actin, and endomembrane trafficking.

Purpose of the Study:

• To investigate the role of the PLD signaling pathway in the development of the marine brown alga Silvetia compressa.
• To understand how PLD activation and PA production influence cellular structures and division.

Main Methods:

• Treatment of Silvetia compressa zygotes with 1-butanol and 2-butanol to activate the PLD enzyme.
• Analysis of the effects of butanol treatment on microtubule organization and cell division.
• Preliminary investigation of diacylglycerol kinase (DAGK) inhibition on microtubule organization.

Main Results:

• Both 1-butanol and 2-butanol disrupted microtubule organization and cell division, with 1-butanol showing greater potency.
• 1-butanol acts as a transphosphatidylation substrate, reducing PA production, while 2-butanol does not.
• Inhibition of DAGK led to the loss of centrosomal MTs and the formation of cortical MT cages, similar to 1-butanol treatment effects.
• These results question whether butyl alcohol's effects are due to reduced PA levels or direct PLD activation.

Conclusions:

• Perturbation of either the PLD or PLC signaling pathway can lead to cortical stabilization and/or nucleation of microtubule arrays.
• The study highlights the complex interplay between phospholipid signaling and cytoskeletal dynamics in algal development.