Allregulin (ARLN)

Allregulin (ARLN) is a small endogenous transmembrane peptide regulator of the sarcoplasmic/endoplasmic reticulum calcium ATPases (SERCA), which are responsible for maintaining intracellular calcium homeostasis by transporting calcium ions from the cytosol into the sarcoplasmic or endoplasmic reticulum[1][2][7]. Allregulin inhibits SERCA—specifically the ATP2A2/SERCA2 and ATP2A3/SERCA3 isoforms—by decreasing their apparent affinity for Ca²⁺, thereby acting as a negative regulator of calcium uptake into the ER/SR[1][2][7]. This regulation is crucial for proper muscle function and cardiac physiology, as disrupted SERCA activity leads to pathological changes in contractility and calcium signaling[2][4]. Allregulin belongs to a family of SERCA regulatory micropeptides called "regulins," which include phospholamban, sarcolipin, myoregulin, endoregulin, and others, each with distinct tissue specificity and regulatory profiles[2]. The gene encoding Allregulin is located on chromosome 4 (chromosomal locus 4q13.3) and is sometimes referred to by former names, such as C4orf3 or HCV F-transactivated protein 1[1][3][5]. Current research into Allregulin’s physiological and potential pathological roles is ongoing, but it is not yet established as a drug target, clinical biomarker, or the subject of direct pharmacological intervention[1][2][7].

Other names

Sarcoplasmic/endoplasmic reticulum calcium ATPase regulator ARLNSERCA regulator ARLNC4orf3ALNHCV F-transactivated protein 1HCVFTP1hepatitis C virus F protein-transactivated protein 1another-regulinuncharacterized protein C4orf3SERCA regulator ALN