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Updated: Jun 23, 2025

Study of Protein-protein Interactions in Autophagy Research
Published on: September 9, 2017
CRISPRa Analysis of Phosphoinositide Phosphatases Shows That TMEM55A Is a Positive Regulator of Autophagy
Kiyomi Nigorikawa1,2, Yu Fukushima1, Chinatsu Shimada1
1School of Pharmaceutical Sciences, Hiroshima University.
Abstract:
Transcriptional activation, based on Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) and known as CRISPR activation (CRISPRa), is a specific and safe tool to upregulate endogenous genes. Therefore, CRISPRa is valuable not only for analysis of molecular mechanisms of cellular events, but also for treatment of various diseases. Regulating autophagy has been proposed to enhance effects of some therapies. In this study, we upregulated genes for phosphoinositide phosphatases, SACM1L, PIP4P1, and PIP4P2, using CRISPRa, and their effects on autophagy were examined. Our results suggested that TMEM55A/PIP4P2, a phosphatidylinositol-4,5-bisphosphate 4-phosphatase, positively regulates basal autophagy in 293A cells. Furthermore, it was also suggested that SAC1, a phosphatidylinositol 4-phosphatase, negatively regulates basal autophagic degradation.
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