Cofilin recruits F-actin to SPCA1 and promotes Ca2+-mediated secretory cargo sorting.
Bottom Line: How these proteins interact and activate the pump to facilitate cargo sorting, however, is not known.A 132-amino acid portion of the SPCA1 phosphorylation domain (P-domain) interacted with actin in a CFL-1-dependent manner.Altogether, our findings reveal the mechanism of CFL-1-dependent recruitment of actin to SPCA1 and the significance of this interaction for Ca(2+) influx and secretory cargo sorting.
Affiliation: Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.Show MeSH
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Mentions: We reported previously that actin and CFL-1 interact with SPCA1 at the TGN to facilitate Ca2+-dependent secretory cargo sorting (von Blume et al., 2009, 2011). Therefore, we aimed to investigate whether the interaction between CFL-1 and SPCA1-L2-C1 is crucial for this process. To address this, we generated stable cell lines transduced with either GFP-HA as a control, SPCA1-L1-HA, or SPCA1-L2-C1-HA (Fig. 4 A, scheme). First, we analyzed the localization of the proteins by immunofluorescence microscopy. The cells overexpressing GFP-HA, L1-HA, or L2-C1-HA were fixed and stained with an antibody against HA. All the HA-tagged proteins showed a comparable localization in the cytosol or the nucleus (Fig. 4 A).
Affiliation: Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.