REVIEW: Universal Adapter Protein Bag3 and Small Heat Shock Proteins

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Maria A. Zamotina¹, Lidia K. Muranova¹, Artur I. Zabolotskii¹, Pyotr A. Tyurin-Kuzmin², Konstantin Yu. Kulebyakin², Nikolai B. Gusev^1,2,a*

¹Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia

²Department of Biochemistry and Regenerative Biomedicine, Faculty of Fundamental Medicine, Lomonosov Moscow State University, 119991 Moscow, Russia

^* To whom correspondence should be addressed.

Received: April 26, 2024; Revised: May 20, 2024; Accepted: May 24, 2024

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Bag3 (Bcl-2-associated athanogene 3) protein contains a number of functional domains and interacts with a wide range of different partner proteins, including small heat shock proteins (sHsps) and heat shock protein Hsp70. The ternary Bag3–sHsp–and Hsp70 complex binds denatured proteins and transports them to phagosomes, thus playing a key role in the chaperone-assisted selective autophagy (CASA). This complex also participates in the control of formation and disassembly of stress granules (granulostasis) and cytoskeleton regulation. As Bag3 and sHsps participate in multiple cellular processes, mutations in these proteins are often associated with neurodegenerative diseases and cardiomyopathy. The review discusses the role of sHsps in different processes regulated by Bag3.

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KEY WORDS: Bag3, Hsp70, small heat shock proteins, selective autophagy, proteostasis

DOI: 10.1134/S0006297924090013

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