Annexin A9 is a periplakin interacting partner in membrane-targeted cytoskeletal linker protein complexes

Abstract

Periplakin regulates keratin organisation and participates in the assembly of epidermal cornified envelopes. A proteomic approach identified annexin A9 as a novel interacting partner for periplakin N-terminus. The presence of annexin A9 in complexes with periplakin was confirmed by immunoblotting of proteins immunoprecipitated by anti-HA or anti-annexin A9 antibodies. Both endogenous and GFP-tagged annexin A9 co-localise with endogenous periplakin and transfected periplakin N-terminus at MCF-7 cell borders and aggregate after Okadaic acid treatment. Annexin A9 and periplakin co-localise in the epidermis and annexin A9 is up-regulated in differentiating keratinocytes, but the epidermal annexin A9 expression does not require periplakin. Structured summary of protein interactionsAnnexin-9physically interacts with Periplakin by anti bait co-immunoprecipitation (View interaction) Periplakinphysically interacts with Annexin-9 by anti tag co-immunoprecipitation (View Interaction: 1, 2) Periplakin and Annexin-9colocalize by fluorescence microscopy (View Interaction: 1, 2, 3) Keratin-8 and Periplakincolocalize by fluorescence microscopy (View interaction)