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Extracellular chaperones and proteostasis

Journal Article


Abstract


  • Disease-associated extracellular protein deposition was first documented over a century ago. Remarkably, it has only been in the last decade that attention has been given to identifying and characterising the elements of the proteostasis network that exist outside cells (i.e. extracellular proteostasis). The pioneering work in this field has been led by Senior Professor Mark Wilson (University of Wollongong), who originally proposed that protein folding quality control systems must exist beyond the boundary of the cell membrane in order to protect the proteins that are secreted into the extracellular milieu (1,2). Proteins are a major component of biological fluids including blood plasma, cerebral spinal fluid (CSF), synovial fluid and interstitial fluid. Compared to proteins that are retained within the cytosol, secreted proteins are subjected to relatively harsh conditions in the extracellular milieu. Structural modifications have evolved to increase the stability of extracellular proteins (eg. disulphide bonds, glycosylation). Despite these modifications, many abundant extracellular proteins are susceptible to misfolding in the presence of physiological stressors. For example, albumin, fibrinogen, and ceruloplasmin can be induced to misfold by shear stress conditions that are comparable to those encountered within the bloodstream (3). Also, biological oxidants potently induce the misfolding and aggregation of albumin, fibrinogen and apolipoprotein B-100, which has direct implications on their functions and is implicated in disease (4-6).

Publication Date


  • 2016

Citation


  • Wyatt, A. R. (2016). Extracellular chaperones and proteostasis. Australian Biochemist, 47 (2), 14-17.

Number Of Pages


  • 3

Start Page


  • 14

End Page


  • 17

Volume


  • 47

Issue


  • 2

Place Of Publication


  • https://www.asbmb.org.au/magazine/

Abstract


  • Disease-associated extracellular protein deposition was first documented over a century ago. Remarkably, it has only been in the last decade that attention has been given to identifying and characterising the elements of the proteostasis network that exist outside cells (i.e. extracellular proteostasis). The pioneering work in this field has been led by Senior Professor Mark Wilson (University of Wollongong), who originally proposed that protein folding quality control systems must exist beyond the boundary of the cell membrane in order to protect the proteins that are secreted into the extracellular milieu (1,2). Proteins are a major component of biological fluids including blood plasma, cerebral spinal fluid (CSF), synovial fluid and interstitial fluid. Compared to proteins that are retained within the cytosol, secreted proteins are subjected to relatively harsh conditions in the extracellular milieu. Structural modifications have evolved to increase the stability of extracellular proteins (eg. disulphide bonds, glycosylation). Despite these modifications, many abundant extracellular proteins are susceptible to misfolding in the presence of physiological stressors. For example, albumin, fibrinogen, and ceruloplasmin can be induced to misfold by shear stress conditions that are comparable to those encountered within the bloodstream (3). Also, biological oxidants potently induce the misfolding and aggregation of albumin, fibrinogen and apolipoprotein B-100, which has direct implications on their functions and is implicated in disease (4-6).

Publication Date


  • 2016

Citation


  • Wyatt, A. R. (2016). Extracellular chaperones and proteostasis. Australian Biochemist, 47 (2), 14-17.

Number Of Pages


  • 3

Start Page


  • 14

End Page


  • 17

Volume


  • 47

Issue


  • 2

Place Of Publication


  • https://www.asbmb.org.au/magazine/