The Par complex polarizes the plasma membrane of diverse animal cells using the catalytic activity of atypical Protein Kinase C (aPKC) to pattern substrates. Two upstream regulators of the Par complex, Cdc42 and Par-3, bind separately to the complex to influence its activity in different ways. Each regulator binds a distinct member of the complex, Cdc42 to Par-6 and Par-3 to aPKC, making it unclear how they influence one another's binding. Here we report the discovery that Par-3 binding to aPKC is regulated by aPKC autoinhibition and link this regulation to Cdc42 and Par-3 exchange. The Par-6 PDZ domain activates aPKC binding to Par-3 via a novel interaction with the aPKC kinase domain. Cdc42 and Par-3 have opposite effects on the Par-6 PDZ-aPKC kinase interaction: while the Par-6 kinase domain interaction competes with Cdc42 binding to the complex, Par-3 binding is enhanced by the interaction. The differential effect of Par-3 and Cdc42 on the Par-6 PDZ interaction with the aPKC kinase domain forms an allosteric relay that connects their binding sites and is responsible for the negative cooperativity that underlies Par complex polarization and activity.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11507878 | PMC |
http://dx.doi.org/10.1101/2024.10.18.619144 | DOI Listing |
J Chem Theory Comput
January 2025
Exscientia, Schrödinger Building, Oxford Science Park, Oxford OX4 4GE, U.K.
The development of machine-learning (ML) potentials offers significant accuracy improvements compared to molecular mechanics (MM) because of the inclusion of quantum-mechanical effects in molecular interactions. However, ML simulations are several times more computationally demanding than MM simulations, so there is a trade-off between speed and accuracy. One possible compromise are hybrid machine learning/molecular mechanics (ML/MM) approaches with mechanical embedding that treat the intramolecular interactions of the ligand at the ML level and the protein-ligand interactions at the MM level.
View Article and Find Full Text PDFMicrosyst Nanoeng
December 2024
Research Center for Bionic Sensing and Intelligence, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 518055, Shenzhen, China.
We present a versatile platform for label-free magnetic separation of plasma, tailored to accommodate diverse environments. This innovative device utilizes an advanced long-short alternating double Halbach magnetic array, specifically engineered for optimal magnetic separation. The array's adaptability allows for seamless integration with separation channels of varying sizes, enabling static separation of whole blood.
View Article and Find Full Text PDFDiscov Oncol
December 2024
Department of Cerebrovascular Disease, Suining First People's Hospital, No. 2 Wentao Road, High-Tech Zone, Suining, 629000, Sichuan, China.
The immune response plays a pivotal role in tumor progression and therapy. However, the influence of protein PAR polymerases (PARPs) modifications on cell infiltration within the tumor microenvironment (TME) remains insufficiently understood. In this study, the Clinical and RNA sequencing data we performed a comprehensive analysis of PARPs modification patterns, exploring their associations with TME cell infiltration were acquired from the Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) database.
View Article and Find Full Text PDFVavilovskii Zhurnal Genet Selektsii
November 2024
Institute of Chemical Biology and Fundamental Medicine of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
DNA repair is a most important cellular process that helps maintain the integrity of the genome and is currently considered by researchers as one of the factors determining the maximum lifespan. The central regulator of the DNA repair process is the enzyme poly(ADP-ribose)polymerase 1 (PARP1). PARP1 catalyzes the synthesis of poly(ADP-ribose) polymer (PAR) upon DNA damage using nicotinamide adenine dinucleotide (NAD+) as a substrate.
View Article and Find Full Text PDFJ Biol Chem
December 2024
Institute of Molecular Biology Department of Chemistry and Biochemistry 1229 University of Oregon Eugene, OR 97403. Electronic address:
The Par complex polarizes the plasma membrane of diverse animal cells using the catalytic activity of atypical Protein Kinase C (aPKC) to pattern substrates. Two upstream regulators of the Par complex, Cdc42 and Par-3, bind separately to the complex to influence its activity in different ways. Each regulator binds a distinct member of the complex, Cdc42 to Par-6 and Par-3 to aPKC, making it unclear how they influence one another's binding.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!