TY - JOUR
T1 - Amino acids modulate liquid-liquid phase separation in vitro and in vivo by regulating protein-protein interactions
AU - Xu, Xufeng
AU - Rebane, Aleksander A.
AU - Julia, Laura Roset
AU - Rosowski, Kathryn A.
AU - Dufresne, Eric R.
AU - Stellacci, Francesco
N1 - Publisher Copyright:
Copyright © 2024 the Author(s). Published by PNAS.
PY - 2024/12/10
Y1 - 2024/12/10
N2 - Liquid-liquid phase separation (LLPS) is an intracellular process widely used by cells for many key biological functions. It occurs in complex and crowded environments, where amino acids (AAs) are vital components. We have found that AAs render the net interaction between proteins more repulsive. Here, we find that some AAs efficiently suppress LLPS in test tubes (in vitro). We then screen all the proteinogenic AAs and find that three specific AAs, including proline, glutamine, and glycine, significantly suppressed the formation of stress granules (SGs) in U2OS and HeLa cell lines (in vivo) irrespective of stress types. We also observe the effect in primary fibroblast cells, a viable cell model for neurodegenerative disorders. Kinetic studies by live-cell microscopy show that the presence of AAs not only slows down the formation but also decreases the saturating number and prevents the coalescence of SGs. We finally use sedimentation-diffusion equilibrium analytical ultracentrifuge (SE-AUC) to demonstrate that the suppression effects of AAs on LLPS may be due to their modulation in protein-protein and RNA-RNA interactions. Overall, this study reveals an underappreciated role of cellular AAs, which may find biomedical applications, especially in treating SG-associated diseases.
AB - Liquid-liquid phase separation (LLPS) is an intracellular process widely used by cells for many key biological functions. It occurs in complex and crowded environments, where amino acids (AAs) are vital components. We have found that AAs render the net interaction between proteins more repulsive. Here, we find that some AAs efficiently suppress LLPS in test tubes (in vitro). We then screen all the proteinogenic AAs and find that three specific AAs, including proline, glutamine, and glycine, significantly suppressed the formation of stress granules (SGs) in U2OS and HeLa cell lines (in vivo) irrespective of stress types. We also observe the effect in primary fibroblast cells, a viable cell model for neurodegenerative disorders. Kinetic studies by live-cell microscopy show that the presence of AAs not only slows down the formation but also decreases the saturating number and prevents the coalescence of SGs. We finally use sedimentation-diffusion equilibrium analytical ultracentrifuge (SE-AUC) to demonstrate that the suppression effects of AAs on LLPS may be due to their modulation in protein-protein and RNA-RNA interactions. Overall, this study reveals an underappreciated role of cellular AAs, which may find biomedical applications, especially in treating SG-associated diseases.
KW - amino acid
KW - biomolecular condensate
KW - liquid-liquid phase separation
KW - protein-protein interactions
KW - stress granule
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U2 - 10.1073/pnas.2407633121
DO - 10.1073/pnas.2407633121
M3 - Article
C2 - 39642205
AN - SCOPUS:85211584924
SN - 0027-8424
VL - 121
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 50
M1 - e2407633121
ER -