14-3-3 isoforms bind directly exon B of the 5'-UTR of human surfactant protein A2 mRNA.

Autor:	Noutsios GT; Center for Host Defense, Inflammation, and Lung Disease (CHILD), Research Department of Pediatrics, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania; and., Ghattas P; Center for Host Defense, Inflammation, and Lung Disease (CHILD), Research Department of Pediatrics, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania; and., Bennett S; Center for Host Defense, Inflammation, and Lung Disease (CHILD), Research Department of Pediatrics, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania; and., Floros J; Center for Host Defense, Inflammation, and Lung Disease (CHILD), Research Department of Pediatrics, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania; and Department of Obstetrics and Gynecology, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania jfloros@psu.edu.
Jazyk:	angličtina
Zdroj:	American journal of physiology. Lung cellular and molecular physiology [Am J Physiol Lung Cell Mol Physiol] 2015 Jul 15; Vol. 309 (2), pp. L147-57. Date of Electronic Publication: 2015 May 22.
DOI:	10.1152/ajplung.00088.2015
Abstrakt:	Human surfactant protein (SP) A (SP-A), an innate immunity molecule, is encoded by two genes, SFTPA1 and SFTPA2. The 5'-untranslated splice variant of SP-A2 (ABD), but not SP-A1 (AD), contains exon B (eB). eB is an enhancer for transcription and translation and contains cis-regulatory elements. Specific trans-acting factors, including 14-3-3, bind eB. The 14-3-3 protein family contains seven isoforms that have been found by mass spectrometry in eB electromobility shift assays (Noutsios et al. Am J Physiol Lung Cell Mol Physiol 304: L722-L735, 2013). We used four different approaches to investigate whether 14-3-3 isoforms bind directly to eB. 1) eB RNA pulldown assays showed that 14-3-3 isoforms specifically bind eB. 2) RNA electromobility shift assay complexes were formed using purified 14-3-3 isoforms β, γ, ε, η, σ, and τ, but not isoform ζ, with wild-type eB RNA. 3 and 4) RNA affinity chromatography assays and surface plasmon resonance analysis showed that 14-3-3 isoforms β, γ, ε, η, σ, and τ, but not isoform ζ, specifically and directly bind eB. Inhibition of 14-3-3 isoforms γ, ε, η, and τ/θ with shRNAs in NCI-H441 cells resulted in downregulation of SP-A2 levels but did not affect SP-A1 levels. However, inhibition of 14-3-3 isoform σ was correlated with lower levels of SP-A1 and SP-A2. Inhibition of 14-3-3 isoform ζ/δ, which does not bind eB, had no effect on expression levels of SP-A1 and SP-A2. In conclusion, the 14-3-3 protein family affects differential regulation of SP-A1 and SP-A2 by binding directly to SP-A2 5'-UTR mRNA. (Copyright © 2015 the American Physiological Society.)
Databáze:	MEDLINE
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