title: SERCaMP: a carboxy-terminal protein modification that enables monitoring of ER calcium homeostasis.
abstract: Endoplasmic reticulum (ER) calcium homeostasis is disrupted in diverse pathologies, including neurodegeneration, cardiovascular diseases, and diabetes. Temporally defining calcium dysregulation during disease progression, however, has been challenging. Here we describe secreted ER calcium-monitoring proteins (SERCaMPs), which allow for longitudinal monitoring of ER calcium homeostasis. We identified a carboxy-terminal modification that is sufficient to confer release of a protein specifically in response to ER calcium depletion. A Gaussia luciferase (GLuc)-based SERCaMP provides a simple and sensitive method to monitor ER calcium homeostasis in vitro or in vivo by analyzing culture medium or blood. GLuc-SERCaMPs revealed ER calcium depletion in rat primary neurons exposed to various ER stressors. In vivo, ER calcium disruption in rat liver was monitored over several days by repeated sampling of blood. Our results suggest that SERCaMPs will have broad applications for the long-term monitoring of ER calcium homeostasis and the development of therapeutic approaches to counteract ER calcium dysregulation.
authors.affiliation: Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Henderson
authors.affiliation: Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224.
authors.forename: Emily S
authors.initials: ES
authors.lastname: Wires
authors.affiliation: Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Trychta
authors.affiliation: Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224.
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Richie
authors.affiliation: Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224 BHarvey@intra.nida.nih.gov.
authors.forename: Brandon K
authors.initials: BK
authors.lastname: Harvey
mesh_terms: D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D000229:Dependovirus / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D059865:Endoplasmic Reticulum Stress; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006706:Homeostasis; D006801:Humans; D008099:Liver / Q000378:metabolism; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D061251:Primary Cell Culture; D015202:Protein Engineering; D021381:Protein Transport; D051381:Rats; D017207:Rats, Sprague-Dawley; D018000:Receptors, Peptide / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D014161:Transduction, Genetic
chemical_list: D000697:Central Nervous System Stimulants; C064459:KDEL receptor; D018000:Receptors, Peptide; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D002110:Caffeine; D008156:Luciferases; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D002118:Calcium