Molecular mechanisms of small heat shock protein^|^ndash;related disease and its therapeutic strategies

Drought is one of the most important abiotic stresses that seriously affects cotton growth, development, and production worldwide. However, the molecular mechanism, key pathway, and responsible genes for drought tolerance incotton have not been stated clearly. In this research, high-throughput next generation sequencing technique was utilized to investigate gene expression profiles of three cotton species (Gossypium hirsutum, Gossypium arboreum, and Gossypium barbadense L.) under drought stress. A total of 6968 differentially expressed genes (DEGs) were identified, where 2053, 742, and 4173 genes were tested as statistically significant; 648, 320, and 1998 genes were up-regulated, and 1405, 422, and 2175 were down-regulated in TM-1, Zhongmian-16, and Pima4-S, respectively. Total DEGs were annotated and classified into functional groups under gene ontology analysis. The biological process was present only in tolerant species(TM-1), indicating drought tolerance condition. The Kyoto encyclopedia of genes and genomes showed the involvement of plant hormone signal transduction and metabolic pathways enrichment under drought stress. Several transcription factors associated with ethylene-responsive genes (ICE1, MYB44, FAMA, etc.) were identified as playing key roles in acclimatizing to drought stress. Drought also caused significant changes in the expression of certain functional genes linked to abscisic acid (ABA) responses (NCED, PYL, PP2C, and SRK2E), reactive oxygen species (ROS) related in small heat shock protein and 18.1 kDa I heat shock protein, YLS3, and ODORANT1 genes. These results will provide deeper insights into the molecular mechanisms of drought stress adaptation in cotton.

Download Full-text

Heat Shock Protein 22 in Physiological and Pathological Hearts: Small Molecule, Large Potentials

Cells ◽

10.3390/cells11010114 ◽

2021 ◽

Vol 11 (1) ◽

pp. 114

Author(s):

Xiaonan Sun ◽

Sharadhi Siri ◽

Amirah Hurst ◽

Hongyu Qiu

Keyword(s):

Heat Shock ◽

Heat Shock Protein ◽

Molecular Mechanisms ◽

Heart Diseases ◽

Pressure Overload ◽

Small Heat Shock Protein ◽

Cardiac Metabolism ◽

Vital Role ◽

Post Translational Modification ◽

Heat Shock Protein 22

Small heat shock protein 22 (HSP22) belongs to the superfamily of heat shock proteins and is predominantly expressed in the heart, brain, skeletal muscle, and different types of cancers. It has been found that HSP22 is involved in variant cellular functions in cardiomyocytes and plays a vital role in cardiac protection against cardiomyocyte injury under diverse stress. This review summarizes the multiple functions of HSP22 in the heart and the underlying molecular mechanisms through modulating gene transcription, post-translational modification, subcellular translocation of its interacting proteins, and protein degradation, facilitating mitochondrial function, cardiac metabolism, autophagy, and ROS production and antiapoptotic effect. We also discuss the association of HSP22 in cardiac pathologies, including human dilated cardiomyopathy, pressure overload-induced heart failure, ischemic heart diseases, and aging-related cardiac metabolism disorder. The collected information would provide insights into the understanding of the HSP22 in heart diseases and lead to discovering the therapeutic targets.

Download Full-text

The small heat-shock protein αB-crystallin uses different mechanisms of chaperone action to prevent the amorphous versus fibrillar aggregation of α-lactalbumin

Biochemical Journal ◽

10.1042/bj20121187 ◽

2012 ◽

Vol 448 (3) ◽

pp. 343-352 ◽

Cited By ~ 38

Author(s):

Melissa Kulig ◽

Heath Ecroyd

Keyword(s):

Heat Shock ◽

Heat Shock Protein ◽

Molecular Mechanisms ◽

Amyloid Fibrils ◽

Conformational Stability ◽

Critical Role ◽

Small Heat Shock Protein ◽

Αb Crystallin ◽

Amorphous Aggregation ◽

Fibril Aggregates

Stress conditions can destabilize proteins, promoting them to unfold and adopt intermediately folded states. Partially folded protein intermediates are unstable and prone to aggregation down off-folding pathways leading to the formation of either amorphous or amyloid fibril aggregates. The sHsp (small heat-shock protein) αB-crystallin acts as a molecular chaperone to prevent both amorphous and fibrillar protein aggregation; however, the precise molecular mechanisms behind its chaperone action are incompletely understood. To investigate whether the chaperone activity of αB-crystallin is dependent upon the form of aggregation (amorphous compared with fibrillar), bovine α-lactalbumin was developed as a model target protein that could be induced to aggregate down either off-folding pathway using comparable buffer conditions. Thus when α-lactalbumin was reduced it aggregated amorphously, whereas a reduced and carboxymethylated form aggregated to form amyloid fibrils. Using this model, αB-crystallin was shown to be a more efficient chaperone against amorphously aggregating α-lactalbumin than when it aggregated to form fibrils. Moreover, αB-crystallin forms high molecular mass complexes with α-lactalbumin to prevent its amorphous aggregation, but prevents fibril formation via weak transient interactions. Thus, the conformational stability of the protein intermediate, which is a precursor to aggregation, plays a critical role in modulating the chaperone mechanism of αB-crystallin.

Download Full-text