Angiotensin II-induced angiotensin II type I receptor lysosomal degradation studied by fluorescence lifetime imaging microscopy

Hewang Li; Peiying Yu; Robin A. Felder; Ammasi Periasamy; Pedro A. Jose M.D.

doi:10.1117/12.811032

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13 February 2009 Angiotensin II-induced angiotensin II type I receptor lysosomal degradation studied by fluorescence lifetime imaging microscopy

Hewang Li; Peiying Yu; Robin A. Felder; Ammasi Periasamy; Pedro A. Jose M.D.

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Proceedings Volume 7183, Multiphoton Microscopy in the Biomedical Sciences IX; 71832G (2009) https://doi.org/10.1117/12.811032
Event: SPIE BiOS, 2009, San Jose, California, United States

Abstract

Upon activation, the angiotensin (Ang) II type 1 receptor (AT₁Rs) rapidly undergoes endocytosis. After a series of intracellular processes, the internalized AT₁Rs recycle back to the plasma membrane or are trafficked to proteasomes or lysosomes for degradation. We recently reported that AT₁Rs degrades in proteasomes upon stimulation of the D5 dopamine receptor (D5R) in human renal proximal tubule and HEK-293 cells. This is in contrast to the degradation of AT1R in lysosomes upon binding Ang II. However, the dynamic regulation of the AT₁Rs in lysosomes is not well understood. Here we investigated the AT₁Rs lysosomal degradation using FRET-FLIM in HEK 293 cells heterologously expressing the human AT1R tagged with EGFP as the donor fluorophore. Compared to its basal state, the lifetime of AT₁Rs decreased after a 5-minute treatment with Ang II treatment and colocalized with Rab5 but not Rab7 and LAMP1. With longer Ang II treatment (30 min), the AT₁Rs lifetime decreased and co-localized with Rab5, as well as Rab7 and LAMP1. The FLIM data are corroborated with morphological and biochemical co-immunoprecipitation studies. These data demonstrate that Ang II induces the internalization of AT₁Rs into early sorting endosomes prior to trafficking to late endosomes and subsequent degradation in lysosomes.

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Hewang Li, Peiying Yu, Robin A. Felder, Ammasi Periasamy, and Pedro A. Jose M.D. "Angiotensin II-induced angiotensin II type I receptor lysosomal degradation studied by fluorescence lifetime imaging microscopy", Proc. SPIE 7183, Multiphoton Microscopy in the Biomedical Sciences IX, 71832G (13 February 2009); https://doi.org/10.1117/12.811032