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Updated: Jun 26, 2026

Assessing Autophagic Flux by Measuring LC3, p62, and LAMP1 Co-localization Using Multispectral Imaging Flow Cytometry
Published on: July 21, 2017
Bax-/- bak-/- cells exhibit p27 Thr198 phosphorylation and autophagy
Qinghua Cui1, Mayda Valentin, Yelena Janumyan
1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
Abstract:
Cell cycle arrest in G(0) and autophagy share features in common. The Bcl-2 family exerts cell cycle effects in addition to regulating apoptosis. Bcl-2 and Bcl-x(L) upregulate p27 and promote G(0) arrest. Recently, we asked whether autophagy was involved in Bcl-2 and Bcl-x(L)-mediated cell cycle arrest, and found that autophagy was activated, but not required, for G(0) arrest. We also discovered that the cell cycle function of Bcl-2 and Bcl-x(L) was dependent on Bax and Bak, and in bax(-/-) bak(-/-) double knockout cells, features of G(0) quiesecence were already present and p27 was constitutively elevated. Here, we queried the presence of autophagy in bax(-/-) bak(-/-) double knockout cells, and report the phosphorylation of p27 at Thr198, which is known to occur in autophagy, as well as constitutive Atg5 induction and LC3-I to -II conversion. These findings in bax(-/-) bak(-/-) cells suggest that a physiological role of Bax and Bak may be the suppression of autophagy.
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