Intracellular degradation of low-density lipoprotein probed with two-color fluorescence microscopy

LAMP1;Fluorescence microscopy;Low-density lipoprotein;Lysosome;Endosome;Rab7

Humphries, William Henry, IV ; Chemistry and Biochemistry

University:Georgia Institute of Technology

Department:Chemistry and Biochemistry

关键词: LAMP1;    Fluorescence microscopy;    Low-density lipoprotein;    Lysosome;    Endosome;    Rab7;   

Others  :  https://smartech.gatech.edu/bitstream/1853/42832/1/humphriesiv_william_h_201112_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

The vesicle-mediated degradation of low-density lipoprotein (LDL) is an essential cellular function due to its role in cellular biosynthesis of membranes and steroids. Using multi-color single particle tracking fluorescence microscopy, the intracellular degradation of LDL was probed in live, intact cells. Unique to these experiments is the direct observation of LDL degradation using an LDL-based probe that increases fluorescence intensity upon degradation. Specifically, individual LDL particles were labeled with multiple fluorophores resulting in a quenched fluorescent signal. The characteristics of the vesicle responsible for degradation were determined and the vesicle dynamics involved in LDL degradation were quantified. Visualization of early endosomes, late endosomes and lysosomes was accomplished by fluorescently labeling vesicles with variants of GFP. Transient colocalization of LDL with specific vesicles and the intensity of the LDL particle were measured simultaneously. These studies, which are the first to directly observe the degradation of LDL within a cell, strive to completely describe the endo-lysosomal pathway and quantify the dynamics of LDL degradation in cells.