Related Experiment Video
Updated: Aug 7, 2026

Heterokaryon Technique for Analysis of Cell Type-specific Localization
Published on: March 11, 2011
[Study of localization and translocation of human high mobility group protein B1 in eukaryotic cells]
Jia Xu1, Zhi-feng Liu, Juan Wang
1Department of Pathophysiology and Key Laboratory of Functional Proteomics of Guangdong Province, Southern Medical University, Guangzhou 510515, Guangdong, China. graceXjj@126.com
Objective:
To observe the localization and translocation of human high mobility group protein B1 (HMGB1) protein in eukaryotic cells.
Methods:
The vector that expressed the fusion protein of human HMGB1 and enhanced green fluorescent protein (EGFP) in mammalian cells were constructed. HMGB1 and EGFP were subcloned into hytohemagglutinin (HA) tagged vector pcDNA3-HA by two steps, the construct of which was then transfected into 293A cells and observed with fluorescence microscope.
Results:
The recombinant plasmid was verified by enzyme digestion, polymerase chain reaction (PCR) and sequence analysis, and the fusion protein was highly expressed in 293A cells. With fluorescence microscopy the green fluorescence was found to be distributed in the nuclei. Eighteen hours after the stimulation with tumor necrosis factor-alpha (TNF-alpha), it was found to have translocated into the cytoplasm in some of the cells.
Conclusion:
The expression vector for HMGB1-EGFP fusion protein is successfully constructed and effectively expressed in mammalian cells, and it can serve as an important tool in the study of the signal pathway of HMGB1 in mammalian cells.
Related Concept Videos
Overview of Protein Sorting and Transport
Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation. In gated transport, folded...
Post-translational Translocation of Proteins to the RER
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
Regulated mRNA Transport
Bacterial Translocation and Protein Secretion
Cotranslational Protein Translocation
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Nuclear Protein Sorting
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...

