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Phospholamban pentamer
Symbol Phospholamban
Pfam PF04272
InterPro IPR005984
SCOP 1fjk
TCDB 8.A.11
OPM family 70
OPM protein 1zll
Available PDB structures:

1n7lA:1-52 1plnD:35-52 1k9nA:35-52 1plp :1-24 1zllE:1-52 1kchA:35-52 1pslC:35-52 1fjkA:1-52 1fjpA:1-52

Human phospholamban
Symbol PLN
Alt. Symbols PLB
Entrez 5350
HUGO 9080
OMIM 172405
RefSeq NM_002667
UniProt P26678
Other data
Locus Chr. 6 q22.1

Phospholamban is a 52 amino acid integral membrane protein that regulates the Ca2+ pump in cardiac muscle cells.

Dephosphorylated phospholamban interacts with the Ca2+ ATPase pump (SERCA) to lower its activity and sensitivity to Ca2+, thus decreasing Ca2+ uptake into the sarcoplasmic reticulum (SR). Phospholamban is phosphorylated by Protein Kinase A, inducing an order-to-disorder transition, activating the SERCA. Thus, when phospholamban is phosphorylated, its interaction with SERCA is reduced, resulting in an increase in Ca2+ transport into the SR.

Because phospholamban is a substrate for PKA, which is activated with beta-adrenergic stimulation, one would expect relaxation to be favored when PKA is activated. However, this also means that more Ca2+ is stored in the SR and thus more is available for release; this would increase contractility.

Gene knockout of phospholamban results in animals with hyperdynamic hearts, with little apparent negative consequence.


  • Karim, C. B., T. L. Kirby, Z. Zhang, Y. Nesmelov, and D. D. Thomas. 2004. Phospholamban structural dynamics in lipid bilayers probed by a spin label rigidly coupled to the peptide backbone. Proc Natl Acad Sci USA, 101(40): 14437-14442. Entrez PubMed 15448204
  • Brittsan, A. G. & Kranias, E. G. Phospholamban and cardiac contractile function. J. Mol. Cell. Cardiol. 32, 2131-2139 (2000). Entrez PubMed 11112989

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Phospholamban". A list of authors is available in Wikipedia.
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