Small heat shock proteins (sHSPs) and the related alpha-crystallins are ubiquitous chaperones linked to neurodegenerative diseases, myopathies, and cataract. To better define their mechanism of chaperone action, we used hydrogen/deuterium exchange and mass spectrometry (HXMS) to monitor conformational changes during complex formation between the structurally defined sHSPs, pea PsHsp18.1, and wh...

Two mutations (K141E, K141N) in the small heat shock protein (sHSP) HSP22 (HSPB8) are associated with the inherited peripheral motor neuron disorders distal hereditary motor neuropathy type II and axonal Charcot-Marie-Tooth disease type 2L. HSP22 is known to form homodimers, heterodimers with other sHSPs, and larger oligomers. In an effort to elucidate the cellular basis for these diseases, we ...

Small heat shock proteins (sHsps) are molecular chaperones that prevent the aggregation of nonnative proteins. The sHsps investigated to date mostly form large, oligomeric complexes. The typical bacterial scenario seemed to be a two-component sHsps system of two homologous sHsps, such as the Escherichia coli sHsps IbpA and IbpB. With a view to expand our knowledge on bacterial sHsps, we analyze...

Small heat shock proteins (sHsps) maintain cellular homeostasis by preventing stress and disease-induced protein aggregation. While it is known that hydrophobicity impacts the ability of sHsps to bind aggregation-prone denaturing proteins, the complex quaternary structure of globular sHsps has made understanding the significance of specific changes in hydrophobicity difficult. Here we used reco...

Small heat shock protein (sHsp) responses were studied for two evergreen perennial shrubs in the northern California chaparral; one common on warm, south-facing slopes (Ceanothus cuneatus), and the other on cooler, north-facing slopes (Prunus ilicifolia). Small Hsp expression was induced experimentally for field collected leaves. Leaf collections were made where the species co-occur. Small Hsp ...

Alpha-casein, more specifically known as αS-casein, is a predominant milk protein with important nutritional properties. αS-Casein, composed of two individual gene products, αS1and αS2-casein, has been described in the past few decades as having molecular chaperone properties. In performing as molecular chaperones, αScasein and its purified constituent proteins, αS1and αS2-casein, stabilise a w...

Small heat shock proteins (sHSPs) are virtually ubiquitous stress proteins that are also found in many normal tissues and accumulate in diseases of protein folding. They generally act as ATP-independent chaperones to bind and stabilize denaturing proteins that can be later reactivated by ATP-dependent Hsp70/DnaK, but the mechanism of substrate capture by sHSPs remains poorly understood. A major...

Compared with small heat shock proteins (sHSPs) in other organisms, those in plants are the most abundant and diverse. However, the molecular mechanisms by which sHSPs are involved in cell protection remain unknown. Here, we characterized the role of HSP21, a plastid nucleoid-localized sHSP, in chloroplast development under heat stress. We show that an Arabidopsis thaliana knockout mutant of HS...

How small heat shock proteins (sHsps) might empower proteostasis networks to control beneficial prions or disassemble pathological amyloid is unknown. Here, we establish that yeast sHsps, Hsp26 and Hsp42, inhibit prionogenesis by the [PSI+] prion protein, Sup35, via distinct and synergistic mechanisms. Hsp42 prevents conformational rearrangements within molten oligomers that enable de novo prio...

Small heat shock proteins (sHSPs) can regulate protein folding and protect cells from stress. To investigate the role of sHSPs in the silk-producing insect Antheraea pernyi response to microorganisms, a sHsp gene termed as Ap-sHSP21.4, was identified. This gene encoded a 21.4 kDa protein which shares the conserved structure of insect sHsps and belongs to sHSP21.4 family. Ap-sHSP21.4 was highly ...