Single-molecule observations of human small heat shock proteins in complex with aggregation-prone client proteins

Rice, L; Marzano, N; Cox, D; Skewes, B; van Oijen, AM; Ecroyd, H

Journal article

Single-molecule observations of human small heat shock proteins in complex with aggregation-prone client proteins

Abstract:: Small heat shock proteins (sHsps) are molecular chaperones that act to prevent the aberrant aggregation of misfolded proteins. Whilst it is suggested that sHsps prevent aggregation by binding to misfolded client proteins, the dynamic and heterogeneous nature of sHsps has hindered attempts to establish the mechanistic details of how sHsp-client protein complexes form. Single-molecule approaches have emerged as a powerful tool to investigate dynamic and heterogeneous interactions such as those that can occur between sHsps and their client proteins. Here, we use total internal reflection fluorescence microscopy to observe and characterise the complexes formed between model aggregation-prone client proteins (firefly luciferase, rhodanese and chloride intracellular channel 1 protein), and the human sHsps αB-crystallin (αB-c; HSPB5) and Hsp27 (HSPB1). We show that small (monomeric or dimeric) forms of both αB-c and Hsp27 bind to misfolded or oligomeric forms of the client proteins at early stages of aggregation, resulting in the formation of soluble sHsp-client complexes. Stoichiometric analysis of these complexes revealed that additional αB-c subunits accumulate onto pre-existing sHsp-client complexes to form larger species - this does not occur to the same extent for Hsp27. Instead, Hsp27-client interactions tend to be more transient than those of αB-c. Elucidating these mechanisms of sHsp function is crucial to our understanding of how these molecular chaperones act to inhibit protein aggregation and maintain cellular proteostasis.

Publication status:: Published

Peer review status:: Peer reviewed

Actions

Email

Email this record

Send the bibliographic details of this record to your email address.

Your Email
Please enter the email address that the record information will be sent to.

-
Your message (optional)
Please add any additional information to be included within the email.
Share
Cite

Cite this record

APA Style

Rice, L., Marzano, N., Cox, D., Skewes, B., van Oijen, A. M., & Ecroyd, H. (2025). Single-molecule observations of human small heat shock proteins in complex with aggregation-prone client proteins. Biochemical Journal, 482(09), 413–432.

MLA Style

Rice, L, et al. “Single-Molecule Observations of Human Small Heat Shock Proteins in Complex with Aggregation-Prone Client Proteins.” Biochemical Journal, vol. 482, no. 09, 2025, pp. 413–32.

Chicago Style

Rice, L, N Marzano, D Cox, B Skewes, AM van Oijen, and H Ecroyd. 2025. “Single-Molecule Observations of Human Small Heat Shock Proteins in Complex with Aggregation-Prone Client Proteins.” Biochemical Journal 482 (09): 413–32.
Print