Paper
25 February 2009 Fluorescence lifetime dynamics of eGFP in protein aggregates with expanded polyQ
Vladimir Ghukasyan, Chih-Chun Hsu, Chia-Rung Liu, Fu-Jen Kao, Tzu-Hao Cheng
Author Affiliations +
Abstract
Expanding a polyglutamine (polyQ) stretch at the N-terminus of huntingtin protein is the main cause of the neurodegenerative disorder Huntington's disease (HD). Expansion of polyQ above 39 residues has an inherent propensity to form amyloid-like fibrils and aggregation of the mutant protein is found to be a critical component for abnormal pathology of HD. Using yeast Saccharomyces cerevisiae as a model system, we have observed a decrease in fluorescence lifetime of the enhanced green fluorescence protein (eGFP) fused to 97 successive glutamine residues (97Q). Compared to the sample expressing evenly distributed eGFP, the 97Q-eGFP fusion proteins show the formation of grain-like particles and the reduction of eGFP lifetime by ~250 ps as measured by time-correlated single-photon counting technique (TCSPC). More importantly, this phenomenon does not appear in Hsp104-deficient cells. The gene product of HSP104 is required for the formation of polyQ aggregates in yeast cells; therefore, the cellular 97Q-eGFP become soluble and evenly distributive in the absence of Hsp104. Under this condition, the lifetime value of 97Q-eGFP is close to the one exhibited by eGFP alone. The independence of the effect of the environmental parameters, such as pH and refraction index is demonstrated. These data indicate that the fluorescence lifetime dynamics of eGFP is linked to the process of polyQ protein aggregation per se.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Vladimir Ghukasyan, Chih-Chun Hsu, Chia-Rung Liu, Fu-Jen Kao, and Tzu-Hao Cheng "Fluorescence lifetime dynamics of eGFP in protein aggregates with expanded polyQ", Proc. SPIE 7183, Multiphoton Microscopy in the Biomedical Sciences IX, 718327 (25 February 2009); https://doi.org/10.1117/12.809403
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Proteins

Luminescence

Green fluorescent protein

Yeast

Picosecond phenomena

Chromophores

Cell death

Back to Top