Sarcolipin

Sarcolipin is a micropeptide protein that in humans is encoded by the SLN gene.^[3][4]

SLN
Available structures PDB Human UniProt search: PDBe RCSB List of PDB id codes 1JDM
Identifiers
Aliases	SLN, sarcolipin
External IDs	OMIM: 602203; GeneCards: SLN; OMA:SLN - orthologs
Gene location (Human) Chr. Chromosome 11 (human)[1] Band 11q22.3 Start 107,707,378 bp[1] End 107,719,693 bp[1]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in thoracic diaphragm triceps brachii muscle glutes biceps brachii Skeletal muscle tissue of biceps brachii Skeletal muscle tissue of rectus abdominis muscle of thigh quadriceps femoris muscle vastus lateralis muscle body of tongue n/a More reference expression data BioGPS More reference expression data
Gene ontology Molecular function ATPase binding enzyme inhibitor activity enzyme regulator activity protein binding Cellular component integral component of membrane endoplasmic reticulum membrane membrane endoplasmic reticulum sarcoplasmic reticulum membrane sarcoplasmic reticulum Biological process positive regulation of protein depolymerization negative regulation of protein-containing complex disassembly negative regulation of calcium ion binding regulation of calcium ion transport negative regulation of catalytic activity negative regulation of calcium ion transmembrane transporter activity calcium ion transport negative regulation of calcium ion import sarcoplasmic reticulum calcium ion transport regulation of relaxation of muscle regulation of ATPase-coupled calcium transmembrane transporter activity positive regulation of cold-induced thermogenesis Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 6588 n/a Ensembl ENSG00000170290 n/a UniProt O00631 n/a RefSeq (mRNA) NM_003063 n/a RefSeq (protein) NP_003054 n/a Location (UCSC) Chr 11: 107.71 – 107.72 Mb n/a PubMed search [2] n/a
Wikidata
View/Edit Human

Function

Sarcoplasmic reticulum Ca²⁺-ATPases are transmembrane proteins that catalyze the ATP-dependent transport of Ca²⁺ from the cytosol into the lumen of the sarcoplasmic reticulum in muscle cells. The SLN gene encodes a small transmembrane proteolipid that regulates several sarcoplasmic reticulum Ca²⁺-ATPases by reducing the accumulation of Ca²⁺ in the sarcoplasmic reticulum without affecting the rate of ATP hydrolysis.^[4]

Ablation of sarcolipin increases atrial Ca²⁺ transient amplitudes and enhanced atrial contractility. Furthermore, atria from sarcolipin-null mice have blunted response to isoproterenol stimulation, implicating sarcolipin as a mediator of beta-adrenergic responses in atria.^[5]

Sarcolipin is an important mediator of muscle based non shivering thermogenesis (NST). It causes the sarcoplasmic reticulum Ca²⁺-ATPases to stop pumping Ca²⁺ ions but continue futilely hydrolysing ATP, thus releasing the energy as heat.^[6][7] Sarcolipin mediated heat production is very important for many organisms to maintain a warm body. In mammals thermogenesis by skeletal muscles is complemented by thermogenesis in the brown adipose tissue and beige adipose tissue.^[8] Sarcolipin mediated heat production in contractile muscles helps endothermic fish like the opah heat its body. Some fishes like the billfishes have a specialised brain heater tissue that is derived from muscles that cannot contract but specialise in producing heat using sarcolipin.

Interactions

SLN (gene) has been shown to interact with PLN^[9][10] and ATP2A1.^[9][10]