2M3B

Serine 16 phosphorylated phospholamban pentamer, Hybrid solution and solid-state NMR structural ensemble

Summary for 2M3B

• Entry DOI: 10.2210/pdb2m3b/pdb
• Related: 2KYV
• NMR Information: BMRB: 18952
• Descriptor: Cardiac phospholamban (1 entity in total)
• Functional Keywords: phospholamban, pln, plb, membrane protein
• Biological source: Oryctolagus cuniculus (rabbit)
• Cellular location: Sarcoplasmic reticulum membrane; Single-pass membrane protein (By similarity): P61015
• Total number of polymer chains: 5
• Total formula weight: 30897.39

Authors

Vostrikov, V.V.,Verardi, R.,Veglia, G. (deposition date: 2013-01-15, release date: 2013-10-30, Last modification date: 2024-10-30)

Primary citation

Vostrikov, V.V.,Mote, K.R.,Verardi, R.,Veglia, G.
Structural Dynamics and Topology of Phosphorylated Phospholamban Homopentamer Reveal Its Role in the Regulation of Calcium Transport.
Structure, 21:2119-2130, 2013

PubMed Abstract: Phospholamban (PLN) inhibits the sarco(endo)plasmic reticulum Ca²⁺-ATPase (SERCA), thereby regulating cardiac diastole. In membranes, PLN assembles into homopentamers that in both the phosphorylated and nonphosphorylated states have been proposed to form ion-selective channels. Here, we determined the structure of the phosphorylated pentamer using a combination of solution and solid-state nuclear magnetic resonance methods. We found that the pinwheel architecture of the homopentamer is preserved upon phosphorylation, with each monomer having an L-shaped conformation. The TM domains form a hydrophobic pore approximately 24 Å long and 2 Å in diameter, which is inconsistent with canonical Ca²⁺-selective channels. Phosphorylation, however, enhances the conformational dynamics of the cytoplasmic region of PLN, causing partial unwinding of the amphipathic helix. We propose that PLN oligomers act as storage for active monomers, keeping SERCA function within a physiological window.

PubMed: 24207128
DOI: 10.1016/j.str.2013.09.008

Experimental method

SOLID-STATE NMR
SOLUTION NMR