TY - JOUR
T1 - Defining the Intramembrane Binding Mechanism of Sarcolipin to Calcium ATPase Using Solution NMR Spectroscopy
AU - Buffy, Jarrod J.
AU - Buck-Koehntop, Bethany A.
AU - Porcelli, Fernando
AU - Traaseth, Nathaniel J.
AU - Thomas, David D.
AU - Veglia, Gianluigi
PY - 2006/4/28
Y1 - 2006/4/28
N2 - Sarcolipin (SLN) is an integral membrane protein that is expressed in both skeletal and cardiac muscle, where it inhibits SERCA (calcium ATPase) by lowering its apparent Ca2+ affinity in a manner similar to that of its homologue phospholamban (PLN). We use solution NMR to map the structural changes occurring within SLN upon interaction with the regulatory target, SERCA, co-reconstituting the two proteins in dodecylphosphocholine (DPC) detergent micelles, a system that preserves the native structure of SLN and the activity of SERCA, with the goal of comparing these interactions with those of the previously studied PLN-SERCA complex. Our analysis of the structural dynamics of SLN in DPC micelles shows this polypeptide to be partitioned into four subdomains: a short unstructured N terminus (residues 1-6), a short dynamic helix (residues 7-14), a more rigid helix (residues 15-26), and an unstructured C terminus (residues 27-31). Upon addition of SERCA, the different domains behave according to their dynamics, molding onto the surface of the enzyme. Remarkably, each domain of SLN behaves in a manner similar to that of the corresponding domains in PLN, supporting the hypothesis that both SLN and PLN bind SERCA in the same groove and with similar mechanisms.
AB - Sarcolipin (SLN) is an integral membrane protein that is expressed in both skeletal and cardiac muscle, where it inhibits SERCA (calcium ATPase) by lowering its apparent Ca2+ affinity in a manner similar to that of its homologue phospholamban (PLN). We use solution NMR to map the structural changes occurring within SLN upon interaction with the regulatory target, SERCA, co-reconstituting the two proteins in dodecylphosphocholine (DPC) detergent micelles, a system that preserves the native structure of SLN and the activity of SERCA, with the goal of comparing these interactions with those of the previously studied PLN-SERCA complex. Our analysis of the structural dynamics of SLN in DPC micelles shows this polypeptide to be partitioned into four subdomains: a short unstructured N terminus (residues 1-6), a short dynamic helix (residues 7-14), a more rigid helix (residues 15-26), and an unstructured C terminus (residues 27-31). Upon addition of SERCA, the different domains behave according to their dynamics, molding onto the surface of the enzyme. Remarkably, each domain of SLN behaves in a manner similar to that of the corresponding domains in PLN, supporting the hypothesis that both SLN and PLN bind SERCA in the same groove and with similar mechanisms.
KW - Ca-ATPase
KW - SERCA
KW - phospholamban
KW - sarcolipin
KW - solution NMR
UR - http://www.scopus.com/inward/record.url?scp=33646110094&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33646110094&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2006.02.005
DO - 10.1016/j.jmb.2006.02.005
M3 - Article
C2 - 16519897
AN - SCOPUS:33646110094
VL - 358
SP - 420
EP - 429
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 2
ER -