Fig. 7: LATS1 induces inactive Beclin-1 self-dimerization.
From: LATS1 but not LATS2 represses autophagy by a kinase-independent scaffold function
a LATS1, but not LATS2, promotes Beclin-1 self-dimerization in a kinase activity-independent manner. HEK293T/17 cells were transfected with indicated plasmids. Cells were collected 72 h later for immunoprecipitation with anti-HA antibody and then immunoblotted for HA, Flag-tagged Beclin-1, and LATS1/2. Input represents analysis of cell lysates before immunoprecipitation. Immunoblots represent three independent experiments. b Quantification of dimerized Beclin-1 (BECN1) protein abundancy pooled from four independent experiments described in (a). Statistical significance was calculated using one-way ANOVA. ***P < 0.001. c LATS2 chimera maintains the ability to promote Beclin-1 self-dimerization. HEK293T/17 cells were transfected with Flag-tagged (Flag-BECN1) and with HA-tagged (HA-BECN1) Beclin-1 and with empty vector (EV) or with vectors encoding for wild-type (WT) LATS1 or LATS2, or LATS2 chimera, as indicated. Cells were collected 72 h later for immunoprecipitation with anti-Flag antibody and then immunoblotted for HA, Flag-tagged Beclin-1, and LATS1/2. Input represents analysis of cell lysates before immunoprecipitation. Immunoblots represent three independent experiments. d Quantification of dimerized Beclin-1 (BECN1) protein abundancy pooled from four independent experiments described in c. Statistical significance was calculated using one-way ANOVA. *P < 0.05. e LATS1-induced ubiquitination at lysine 263 is essential for LATS1-mediated promotion of Beclin-1 self-dimerization. HEK293T/17 cells were transfected with indicated plasmids. Cells were collected 72 h later for immunoprecipitation with anti-Flag antibody and then immunoblotted for HA, Flag-tagged Beclin-1, and LATS1. Input represents analysis of cell lysates before immunoprecipitation. Immunoblots represent three independent experiments. f Quantification of dimerized Beclin-1 (BECN1) protein abundancy pooled from three independent experiments described in e. Statistical significance was calculated using one-way ANOVA. ***P < 0.001, *P < 0.05. g Schematic representation of the role of LATS1 in canonical Hippo signaling (left side) and of its non-canonical role in repressing sorafenib-induced autophagy (right side). LATS1-induced K27-linked ubiquitination of Beclin-1 on K32 and K263 results into its inactivation by self-dimerization and thus to an inhibition of autophagy.
