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: Thereafter, we incubated the major three cytosolic domains known to be required to pump Ca2+ (SPCA1-N-term, A-domain; SPCA1-L1-, A-domain; and SPCA-L2, N- and P-domains; Fig. 1 A) coupled to nickel nitrilotriacetic acid (Ni-NTA) agarose beads with equal amounts of HeLa cell lysates. The beads were then washed, and bound proteins were eluted. Analysis of the samples by Western blotting with antibodies against CFL-1 and β-actin showed that CFL-1 and actin specifically interacted only with SPCA1-L2 (Fig. 1 A).
Affiliation: Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.