Electronic Thesis and Dissertation Repository

Degree

Master of Science

Program

Pharmacology and Toxicology

Supervisor

Dr. Christopher Pin

Abstract

Strict regulation of cytosolic Ca2+ is essential to regulated exocytosis and proper pancreatic acinar cell function, controlled in part by pumps that shuttle Ca2+ out of the cytosol. Our laboratory identified a novel isoform of Secretory Ca2+ ATPase 2 (SPCA2) containing only the carboxy terminus. Pancreatic SPCA2, is an approximately 17-20 kDa, protein encoded by the Atp2c2 gene and is completely absent in Mist1-/- acini.. The focus of this thesis was to understand transcriptional regulation of Atp2c2 in the pancreas. Pancreatic Atp2c2 appears to be transcribed from an alternative transcriptional start site (TSS) and is regulated by MIST1. Bioinformatic analyses identified a truncated Atp2c2 isoform initiated within the 23rd intron of the Atp2c2 gene. Comparative analysis suggested this isoform differs between humans and mice. ChIP-seq analysis identified enrichment for trimethylated (Me3) histone 3(H3) at lysine 4 (K4) in intron 23 in pancreatic tissue, which was confirmed by ChIP-qPCR. ChIP-qPCR also identified enrichment of Acetylated Histone 3 (H3Ac), H3K36Me3, MIST1 and RNA PolII within this region. Luciferase assays and immunofluorescence confirmed this region possessed promoter activity and produced a protein of the correct size. Our results identify a unique TSS for Atp2c2 within the pancreas that is regulated by MIST1.


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