Hsp70: Difference between revisions
No edit summary |
Michal Harel (talk | contribs) No edit summary |
||
| (6 intermediate revisions by 2 users not shown) | |||
| Line 1: | Line 1: | ||
==Structure of Hsp70== | ==Structure of Hsp70== | ||
<StructureSection load='5aqh' size='340' side='right' | <StructureSection load='5aqh' size='340' side='right' caption ='Hsp70 (grey) complex with BAG-1 (green), DMSO, glycerol and inhibitor (PDB code [[5aqh]])' scene=''> | ||
=='''Overview'''== | =='''Overview'''== | ||
Chaperon proteins function to assist in the folding of newly translated proteins unable to fold on their own and even refold proteins that have become nonfunctional due to some type of misfolding. Misfolding can be caused by several different types of stressors such as high temperature, starvation, inflammation, dehydration, or nitrogen deficiency. Heat shock proteins, primarily the Hsp70 family, partially bind to the protein’s exposed hydrophobic surfaces, to promote protein refolding and prevent interactions that might lead to aggregation <ref>Sharma, D., & Masison, D. (2009). Hsp70 Structure, Function, Regulation and Influence on Yeast Prions. Protein & Peptide Letters, 16(6), 571-581. doi:10.2174/092986609788490230</ref>. | Chaperon proteins function to assist in the folding of newly translated proteins unable to fold on their own and even refold proteins that have become nonfunctional due to some type of misfolding. Misfolding can be caused by several different types of stressors such as high temperature, starvation, inflammation, dehydration, or nitrogen deficiency. Heat shock proteins, primarily the '''Hsp70''' family, partially bind to the protein’s exposed hydrophobic surfaces, to promote protein refolding and prevent interactions that might lead to aggregation <ref>Sharma, D., & Masison, D. (2009). Hsp70 Structure, Function, Regulation and Influence on Yeast Prions. Protein & Peptide Letters, 16(6), 571-581. doi:10.2174/092986609788490230</ref>. | ||
There are forms of Hsp70 that are specialized for protein transport into mitochondria and chloroplasts. The proteins transferred into these organelles are not in their mature states yet. Hsp70’s bind to the newly translated polypeptides keeping them unfolded until they are in the organelle. Once they are in the designated organelle, their interiors contain specialized Hsp70’s (mitochondrial or chloroplast Hsp70) that fold the polypeptides into a stable, functional state <ref>Plopper, G. (2016). Cytosolic Proteins Targeted to the Mitochondria or Chloroplasts Contain an N-Terminal Signal Sequence. In Principles of Cell Biology (2nd ed.). Burlington, MA: Jones and Bartlett Learning</ref>. | There are forms of Hsp70 that are specialized for protein transport into mitochondria and chloroplasts. The proteins transferred into these organelles are not in their mature states yet. Hsp70’s bind to the newly translated polypeptides keeping them unfolded until they are in the organelle. Once they are in the designated organelle, their interiors contain specialized Hsp70’s (mitochondrial or chloroplast Hsp70) that fold the polypeptides into a stable, functional state <ref>Plopper, G. (2016). Cytosolic Proteins Targeted to the Mitochondria or Chloroplasts Contain an N-Terminal Signal Sequence. In Principles of Cell Biology (2nd ed.). Burlington, MA: Jones and Bartlett Learning</ref>. | ||
Hsp70 function is critical to homeostasis. Protein aggregation is not typically beneficial to most organisms. For example, protein aggregation in different areas of the brain can lead to certain neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. Hsp70’s promotion of refolding is key to make the misfolded protein functional once again. The many members of the Hsp70 family are highly conserved <ref name="Evans">Evans, C. G., Chang, L., & Gestwicki, J. E. (2010). Heat Shock Protein 70 (Hsp70) as an Emerging Drug Target. Journal of Medicinal Chemistry, 53(12), 4585-4602. doi:10.1021/jm100054f</ref>. This reinforces the presumption that these proteins are vital to most organisms. When something is widely expressed and highly conserved it tells us it has been beneficial to cells and organisms for a very long time and there was no need for change. | Hsp70 function is critical to homeostasis. Protein aggregation is not typically beneficial to most organisms. For example, protein aggregation in different areas of the brain can lead to certain neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. Hsp70’s promotion of refolding is key to make the misfolded protein functional once again. The many members of the Hsp70 family are highly conserved <ref name="Evans">Evans, C. G., Chang, L., & Gestwicki, J. E. (2010). Heat Shock Protein 70 (Hsp70) as an Emerging Drug Target. Journal of Medicinal Chemistry, 53(12), 4585-4602. doi:10.1021/jm100054f</ref>. This reinforces the presumption that these proteins are vital to most organisms. When something is widely expressed and highly conserved it tells us it has been beneficial to cells and organisms for a very long time and there was no need for change. | ||
See also [[Heat Shock Proteins]]. | |||
==''' Structure '''== | ==''' Structure '''== | ||
| Line 38: | Line 40: | ||
Parkinson’s Disease is characterized by the continuing loss of dopaminergic neurons in the substantia nigra pars compacta, with subsequent dopamine decline in the nigrostriatal pathway, and by intracytoplasmic fibrillar <scene name='81/813405/Parkinsons_protein/1'>α-Synuclein</scene> protein aggregates (Lewy Bodies, LB) in the remaining nigral neurons. Hsp70 overexpression demonstrated reduced α-Syn accumulation and toxicity in both mouse and Drosophila Parkinson’s Disease Models <ref>Turturici, G., Sconzo, G., & Geraci, F. (2011). Hsp70 and Its Molecular Role in Nervous System Diseases. Biochemistry Research International, 2011, 1-18. doi:10.1155/2011/618127</ref>. | Parkinson’s Disease is characterized by the continuing loss of dopaminergic neurons in the substantia nigra pars compacta, with subsequent dopamine decline in the nigrostriatal pathway, and by intracytoplasmic fibrillar <scene name='81/813405/Parkinsons_protein/1'>α-Synuclein</scene> protein aggregates (Lewy Bodies, LB) in the remaining nigral neurons. Hsp70 overexpression demonstrated reduced α-Syn accumulation and toxicity in both mouse and Drosophila Parkinson’s Disease Models <ref>Turturici, G., Sconzo, G., & Geraci, F. (2011). Hsp70 and Its Molecular Role in Nervous System Diseases. Biochemistry Research International, 2011, 1-18. doi:10.1155/2011/618127</ref>. | ||
See also [[Heat Shock Proteins]] | |||
== References == | == References == | ||
<references/> | <references/> | ||