Human FLNc-S2233/S2236 phosphorylation after EPS treatment (PRM analysis)

ABSTRACT: The actin-binding protein filamin c (FLNc) is a key mediator in the response of skeletal muscle cells to mechanical stress. In addition to its function as a structural scaffold, FLNc acts as a signaling adaptor which is phosphorylated at S2234 in its mechanosensitive domain 20 (d20) through AKT. Here, we discovered a strong dephosphorylation of FLNc-pS2234 in skeletal myotubes under acute mechanical stress, despite high AKT activity. We found that all three protein phosphatase 1 (PP1) isoforms are part of the FLNc d18-21 interactome. Enzymatic assays demonstrate that PP1 efficiently dephosphorylates FLNc-pS2234 in vitro and in cells upon PP1 activation using specific modulators. FLNc-pS2234 dephosphorylation promotes the interaction with FILIP1, a mediator for filamin degradation. Collectively, we present a model in which dephosphorylation of FLNc d20 by the dominant action of PP1c prevails over AKT activity to promote the binding of the filamin degradation-inducing factor FILIP1 during acute mechanical stress. Note that mouse FLNc S2234/S2237 correspond to S2233 and S2236 in human FLNc.

INSTRUMENT(S):

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Skeletal Muscle Myoblast, Skeletal Muscle Cell

DISEASE(S): Disease Free

SUBMITTER: Julian Bender  

LAB HEAD: Bettina Warscheid

PROVIDER: PXD053234 | Pride | 2025-05-07

REPOSITORIES: Pride