Dynamic changes in the structure and intracellular locale of the mammalian low-molecular-weight heat shock protein

Arrigo, A. P., Suhan, J. P., Welch, W. J. (December 1988) Dynamic changes in the structure and intracellular locale of the mammalian low-molecular-weight heat shock protein. Molecular & Cellular Biology, 8 (12). pp. 5059-71. ISSN 0270-7306

URL: http://www.ncbi.nlm.nih.gov/pubmed/3072471
DOI: 10.1128/MCB.8.12.5059

Abstract

Mammalian cells grown at 37 degrees C contain a single low-molecular-weight heat shock (or stress) protein with an apparent mass of 28 kilodaltons (kDa) whose synthesis increases in cells after exposure to elevated temperatures or other forms of physiologic stress. Herein we present data demonstrating that heat shock protein 28 exists in a number of dynamic states depending upon the physiologic state of the cell. Biochemical fractionation of 37 degrees C cells in the absence of nonionic detergent revealed that the 28-kDa protein partitioned approximately equally between the soluble and insoluble fractions. The addition of detergent in the fractionation procedure resulted in all of the protein distributed within the soluble phase. In contrast, in cells first heat shocked and then fractionated in the presence of detergent, most of the 28-kDa protein was found within the insoluble fraction. These biochemical results appeared entirely consistent with indirect immunofluorescence experiments, demonstrating that the 28-kDa protein resided within the perinuclear region of 37 degrees C cells in close proximity to the Golgi complex. After heat shock treatment, the 28-kDa protein relocalized within the nucleus and resisted detergent extraction. The extent of 28-kDa protein redistribution into the nucleus and its detergent insolubility increased as a function of the severity of the heat shock treatment. With time of recovery from the heat treatment there occurred a gradual return of the 28-kDa protein into the detergent-soluble phase. Concomitant with these changes in 28-kDa protein solubility was a corresponding change in the apparent size of the protein as determined by gel filtration. While at 37 degrees C cells the protein exhibited a mass of 200 to 800 kDa; after heat shock the protein assumed sizes of 2 MDa or greater. Using immunoelectron microscopy, we show an accumulation of these aggregates of 28-kDa protein within the nucleus. Finally, we show that the heat-dependent redistribution of the 28-kDa protein from the cytoplasm into the nucleus was greatly diminished when the cells were first rendered thermotolerant, and we suggest that this simple assay (i.e., 28-kDa protein detergent solubility) may prove useful in evaluating the thermotolerant status of a cell or tissue.

Item Type: Paper
Uncontrolled Keywords: Fibroblasts/cytology/metabolism Fluorescent Antibody Technique Heat Heat-Shock Proteins/analysis/*biosynthesis Hela Cells/metabolism/ultrastructure Humans Immunoblotting Isoelectric Focusing Male Microscopy, Electron Molecular Weight Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. Skin/cytology/metabolism
Subjects: Investigative techniques and equipment > staining techniques
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > fibroblasts
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > fibroblasts
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > fibroblasts

organism description > animal > mammal
CSHL Authors:
Communities: CSHL labs
Depositing User: Gail Sherman
Date: December 1988
Date Deposited: 13 Oct 2017 16:53
Last Modified: 13 Oct 2017 16:53
PMCID: PMC365607
Related URLs:
URI: http://repository.cshl.edu/id/eprint/35113

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