Phospholamban
From Wikipedia, the free encyclopedia
phospholamban
|
|
Identifiers | |
Symbol | PLN PLB |
HUGO | 9080 |
Entrez | 5350 |
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.
[edit] References
- 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
[edit] External links
- UMich Orientation of Proteins in Membranes families/superfamily-70 - Orientations of phospholamban and sarcolipin in membrane]
Second messengers: IP3 | NAADP | cADPR
Intracellular calcium store gates: IP3 receptor | Ryanodine receptor | putative NAADP receptor
Calcium pumps and exchangers: SERCA | Na/Ca antiport | Ca/H antiport
calcium binding protein domains: EF hand domain |C2 domain
Calcium based molecular switches, and kinases: troponin c | CaM | CaM kinases | PKC | NCS
Intracellular Calcium chelators (calcium buffers) and calcium sensors: Calbindin | S100 | pervalbumin | Calretinin | Calsequestrin | Sarcalumenin | Phospholamban | Synaptotagmins
Calcium dependent proteases: Calpain
Calcium dependent cytoskeleton remodeling proteins: Gelsolin
Cell membrane calcium channels: VDCC | TRP | NMDA receptor | AMPA receptor | 5-HT3 receptor | P2X Receptor
Calcium regulated chaperones: calreticulin | calnexin
Calcium based adhesion molecules: cadherin
parathormone | Calcitonin | calcium receptor | vitamin D