PUBLICATION
Expression and localization of the Xenopus laevis small heat shock protein, HSPB6 (HSP20), in A6 kidney epithelial cells
- Authors
- Khamis, I., Chan, D.W., Shirriff, C.S., Campbell, J.H., Heikkila, J.J.
- ID
- ZDB-PUB-160630-5
- Date
- 2016
- Source
- Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 201: 12-21 (Journal)
- Registered Authors
- Keywords
- Amphibian, Cadmium, Frog, Immunoblots, Immunocytochemistry, MG132, Molecular chaperone, Protein aggregates
- MeSH Terms
-
- Amino Acid Sequence
- Animals
- Base Sequence
- Cell Line
- DNA, Complementary/genetics
- Epithelial Cells/metabolism
- Gene Expression
- HSP20 Heat-Shock Proteins/chemistry
- HSP20 Heat-Shock Proteins/genetics*
- HSP20 Heat-Shock Proteins/metabolism*
- Immunohistochemistry
- Kidney/metabolism
- Phylogeny
- Protein Domains
- Sequence Homology, Amino Acid
- Xenopus Proteins/chemistry
- Xenopus Proteins/genetics*
- Xenopus Proteins/metabolism*
- Xenopus laevis/genetics*
- Xenopus laevis/metabolism*
- PubMed
- 27354198 Full text @ Comp. Biochem. Physiol. A Mol. Integr. Physiol.
Citation
Khamis, I., Chan, D.W., Shirriff, C.S., Campbell, J.H., Heikkila, J.J. (2016) Expression and localization of the Xenopus laevis small heat shock protein, HSPB6 (HSP20), in A6 kidney epithelial cells. Comparative biochemistry and physiology. Part A, Molecular & integrative physiology. 201:12-21.
Abstract
Small heat shock proteins (sHSPs) are molecular chaperones that bind to unfolded protein, inhibit the formation of toxic aggregates and facilitate their refolding and/or degradation. Previously, the only sHSPs that have been studied in detail in the model frog system, Xenopus laevis, were members of the HSP30 family and HSPB1 (HSP27). We now report the analysis of X. laevis HSPB6, an ortholog of mammalian HSPB6. X. laevis HSPB6 cDNA encodes a 168 aa protein that contains an α-crystallin domain, a polar C-terminal extension and some possible phosphorylation sites. X. laevis HSPB6 shares 94% identity with a X. tropicalis HSPB6, 65% with turtle, 59% with humans, 49% with zebrafish and only 50% and 43% with X. laevis HSPB1 and HSP30C, respectively. Phylogenetic analysis revealed that X. laevis HSPB6 grouped more closely with mammalian and reptilian HSPB6s than with fish HSPB6. X. laevis recombinant HSPB6 displayed molecular chaperone properties since it had the ability to inhibit heat-induced aggregation of citrate synthase. Immunoblot analysis determined that HSPB6 was present constitutively in kidney epithelial cells and that heat shock treatment did not upregulate HSPB6 levels. While treatment with the proteasomal inhibitor, MG132, resulted in a 2-fold increase in HSPB6 levels, exposure to cadmium chloride produced a slight increase in HSPB6. These findings were in contrast to HSP70, which was enhanced in response to all three stressors. Finally, immunocytochemical analysis revealed that HSPB6 was present in the cytoplasm in the perinuclear region with some in the nucleus.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping