Expression, purification and characterization of C-FADD

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• FADD (Fas-associated death domain) is a key adaptor protein in apoptosis.
• Recent studies reveal FADD's involvement in non-apoptotic cellular processes like development and survival.
• Non-apoptotic FADD functions are regulated by C-terminal serine phosphorylation, a region absent in previously studied FADD structures.

Purpose of the Study:

• To obtain and characterize a FADD variant including the C-terminal region.
• To investigate the structure-function relationship of the FADD C-terminal domain.
• To explore the non-apoptotic roles of FADD.

Main Methods:

• Expression and purification of mouse FADD (80-205), termed C-FADD, from E. coli.
• Characterization of C-FADD using glutaraldehyde cross-linking and circular dichroism (CD) spectroscopy.
• In vitro His-tag pull-down assay to assess CK Ialpha binding activity.

Main Results:

• Purified C-FADD exists as a homogenous monomer.
• CD assay confirmed C-FADD exhibits a typical alpha-helix spectrum.
• In vitro assays demonstrated C-FADD's binding activity with CK Ialpha.

Conclusions:

• A functional FADD variant containing the C-terminal region (C-FADD) was successfully expressed and purified.
• The purified C-FADD retains CK Ialpha-binding activity, essential for its non-apoptotic functions.
• This study provides a foundation for understanding the structure-function dynamics of FADD's C-terminal region in non-apoptotic pathways.