Selective autophagy controls innate immune response through a TAK1/TAB2/SH3PX1 axis

Area of Science:

• Molecular Biology
• Cell Biology
• Immunology

Background:

• Selective autophagy degrades specific cellular components via lysosomes.
• Its role in regulating innate immunity is not well understood.
• The Drosophila immune deficiency (IMD) pathway is crucial for innate immune responses.

Purpose of the Study:

• To investigate the role of selective autophagy in regulating the IMD pathway.
• To identify the specific autophagy and IMD pathway components involved.

Main Methods:

• Investigated interactions between autophagy protein Atg8a and IMD pathway components Tak1 and Tab2.
• Examined the function of Atg8a-interacting protein Sh3px1 in IMD pathway regulation.
• Utilized Drosophila models to study selective autophagy and innate immunity.

Main Results:

• Tak1 (the apical kinase of the IMD pathway) and its co-activator Tab2 are substrates for selective autophagy.
• Tak1 and Tab2 interact with the autophagy protein Atg8a.
• Sh3px1 facilitates the targeting of the Tak1/Tab2 complex to the autophagy machinery via Atg8a, downregulating the IMD pathway.

Conclusions:

• Selective autophagy, mediated by Atg8a and Sh3px1, removes the Tak1/Tab2 signaling complex.
• This mechanism prevents constitutive activation of the IMD pathway in Drosophila.
• Provides mechanistic insight into how selective autophagy regulates innate immune responses.