Rational Design and Intramolecular Cyclization of Hotspot Peptide Segments at YAP-TEAD4 Complex Interface.

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• The Yes-Associated Protein (YAP) is a critical regulator of the Hippo pathway, implicated in various cancers through its interaction with TEA Domain (TEAD) transcription factors.
• Disrupting YAP-TEAD complexes is a potential anti-cancer therapeutic strategy by inhibiting YAP's oncogenic functions.

Purpose of the Study:

• To investigate the crystal structure of the YAP-TEAD4 complex.
• To identify key interaction sites for developing targeted peptide inhibitors.
• To design and characterize self-inhibitory peptides derived from YAP that target the YAP-TEAD4 interaction.

Main Methods:

• Systematic examination of the YAP-TEAD4 complex crystal structure.
• Rational identification of hotspot segments at the complex interface.
• Design and synthesis of two peptides (PS-1 and PS-2) from the YAP-TEAD4 interface.
• Molecular dynamics simulations, energetics analyses, and fluorescence polarization assays to assess peptide properties and binding affinities.

Main Results:

• Two peptides, PS-1 and PS-2, were derived from the YAP-TEAD4 interface.
• Linear PS-2 peptide showed weak binding to TEAD4 (Kd = 190 μM).
• Cyclized versions of PS-2 (PS-2(cyc87,96) and PS-2(cyc86,95)) exhibited significantly enhanced binding affinities (Kd = 21 μM and 45 μM, respectively).

Conclusions:

• PS-1 and PS-2 peptides are conformationally flexible, incurring entropic penalties upon binding.
• Cyclization of PS-2 did not affect direct YAP-TEAD4 interaction but reduced intrinsic disorder and minimized entropic penalties.
• Engineered cyclic peptides demonstrate improved affinity for targeting the YAP-TEAD4 complex, presenting a viable therapeutic approach.