Widespread control of calcium signaling by a family of SERCA-inhibiting micropeptides

• Published in: Science signaling 2016-12, Vol.9 (457), p.ra119-ra119
• Main Authors: Anderson, Douglas M, Makarewich, Catherine A, Anderson, Kelly M, Shelton, John M, Bezprozvannaya, Svetlana, Bassel-Duby, Rhonda, Olson, Eric N
• Format: Article
• Language: English
• Subjects: Animals; Calcium Signaling - drug effects; Calcium-Binding Proteins - chemistry; Calcium-Binding Proteins - pharmacology; Cercopithecus aethiops; COS Cells; Male; Mice; Muscle Proteins - chemistry; Muscle Proteins - pharmacology; Peptides - chemistry; Peptides - pharmacology; Proteolipids - chemistry; Proteolipids - pharmacology; Sarcoplasmic Reticulum Calcium-Transporting ATPases - antagonists & inhibitors; Sarcoplasmic Reticulum Calcium-Transporting ATPases - genetics; Sarcoplasmic Reticulum Calcium-Transporting ATPases - metabolism
• ISSN: 1945-0877; 1937-9145
• DOI: 10.1126/scisignal.aaj1460

Micropeptides function as master regulators of calcium-dependent signaling in muscle. Sarco/endoplasmic reticulum Ca ATPase (SERCA), the membrane pump that promotes muscle relaxation by taking up Ca into the sarcoplasmic reticulum, is directly inhibited by three muscle-specific micropeptides: myoregulin (MLN), phospholamban (PLN), and sarcolipin (SLN). The widespread and essential function of SERCA across diverse cell types has raised questions as to how SERCA is regulated in cells that lack MLN, PLN, and SLN. We identified two transmembrane micropeptides, endoregulin (ELN) and another-regulin (ALN), that share key amino acids with their muscle-specific counterparts and function as direct inhibitors of SERCA pump activity. The distribution of transcripts encoding ELN and ALN mirrored that of SERCA isoform-encoding transcripts in nonmuscle cell types. Our findings identify additional members of the SERCA-inhibitory micropeptide family, revealing a conserved mechanism for the control of intracellular Ca dynamics in both muscle and nonmuscle cell types.