Splice variants of protein disulfide isomerase - identification, distribution and functional characterization in the rat

• Published in: Biochimica et biophysica acta. General subjects Vol. 1867; no. 2; p. 130280
• Main Authors: Chetot, Thomas, Serfaty, Xavier, Carret, Léna, Kriznik, Alexandre, Sophie-Rahuel-Clermont, Grand, Lucie, Jacolot, Maïwenn, Popowycz, Florence, Benoit, Etienne, Lambert, Véronique, Lattard, Virginie
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2023; Elsevier
• Subjects: Animals; Biochemistry, Molecular Biology; Chemical Sciences; consensus sequence; Electron transfer; hematology; Life Sciences; liver; Liver - metabolism; Male; oxidoreductases; Oxidoreductases - metabolism; Protein disulfide isomerase (PDI); protein disulfide-isomerase; Protein Disulfide-Isomerases - genetics; Protein Disulfide-Isomerases - metabolism; Protein Sorting Signals; Protein variant; Rats; RNA, Messenger - metabolism; signal peptide; Splice variant; therapeutics; Protein variant; Electron transfer; Protein disulfide isomerase (PDI); Splice variant
• ISSN: 0304-4165; 1872-8006; 1872-8006
• DOI: 10.1016/j.bbagen.2022.130280

Protein Disulfide Isomerase (PDI) enzyme is an emerging therapeutic target in oncology and hematology. Although PDI reductase activity has been studied with isolated fragments of the protein, natural structural variations affecting reductase activity have not been addressed. In this study, we discovered four coding splice variants of the Pdi pre-mRNA in rats. In vitro Michaelis constants and apparent maximum steady-state rate constants after purification and distribution in different rat tissues were determined. The consensus sequence was found to be the most expressed splice variant while the second most expressed variant represents 15 to 35% of total Pdi mRNA. The third variant shows a quasi-null expression profile and the fourth was not quantifiable. The consensus sequence splice variant and the second splice variant are widely expressed (transcription level) in the liver and even more present in males. Measurements of the reductase activity of recombinant PDI indicate that the consensus sequence and third splice variant are fully active variants. The second most expressed variant, differing by a lack of signal peptide, was found active but less than the consensus sequence. Our work emphasizes the importance of taking splice variants into account when studying PDI-like proteins to understand the full biological functionalities of PDI. •Protein disulfide isomerase (PDI) presents different splicing variants in rat.•PDI splicing variants expression is different between tissues and sexes.•PDI splicing variants do not display the same reductase activity.