Aldolase sequesters WASP and affects WASP/Arp2/3-stimulated actin dynamics

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Biology

Background:

• Fructose-1,6-bisphosphate aldolase (aldolase) is known for its role in glycolysis.
• Aldolase exhibits moonlighting functions, performing tasks beyond its canonical metabolic roles.
• Aldolase interacts with actin and proteins involved in actin dynamics, such as Wiskott-Aldrich Syndrome Protein (WASP).

Purpose of the Study:

• To investigate the role of aldolase in WASP-dependent cellular processes.
• To determine whether aldolase's effects on actin dynamics are due to its catalytic activity or moonlighting functions.

Main Methods:

• In vitro assays measuring actin polymerization inhibition by aldolase.
• Cellular studies involving aldolase knockdown and expression of exogenous aldolase.
• Analysis of aldolase variants with defects in catalytic or actin-binding activity.

Main Results:

• Aldolase inhibits WASP/Arp2/3-dependent actin polymerization in vitro.
• Aldolase knockdown reduces cell motility and cell spreading in cells.
• A catalytically inactive aldolase variant retains the ability to inhibit actin polymerization and rescue cellular defects, while an actin-binding deficient variant does not.

Conclusions:

• Aldolase plays a role in regulating WASP-dependent actin dynamics through its moonlighting functions.
• The actin-binding activity of aldolase, not its catalytic function, is crucial for its effects on cell motility and spreading.