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bioRxiv · 10.1101/2021.12.10.472131

Energetic determinants of the Par-3 interaction with the Par complex

Penkert, R. R.·Vargas, E.·Prehoda, K.
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Abstract

The animal cell polarity regulator Par-3 recruits the Par complex (Par-6 and atypical Protein Kinase C-aPKC) to specific sites on the cell membrane. Although numerous physical interactions have been reported between Par-3 and the Par complex, it has been unclear how each contributes to the overall interaction. Using purified, intact Par complex and a quantitative binding assay, we found that energy for this interaction is provided by Par-3s second and third PDZ protein interaction domains. Both Par-3 PDZ domains bind to aPKCs PDZ Binding Motif (PBM) in the Par complex, with binding energy contributed from aPKCs adjacent catalytic domain. In addition to highlighting the role of Par-3 PDZ interactions with the aPKC kinase domain and PBM in stabilizing Par-3 - Par complex assembly, our results indicate that each Par-3 molecule can potentially recruit two Par complexes to the membrane during cell polarization.

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Penkert, R. R., Vargas, E., Prehoda, K.. 2021-12-11. Energetic determinants of the Par-3 interaction with the Par complex. https://doi.org/10.1101/2021.12.10.472131

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