Growing Rats Respond to a Sulfur Amino Acid–Deficient Diet by Phosphorylation of the {alpha} Subunit of Eukaryotic Initiation Factor 2 Heterotrimeric Complex and Induction of Adaptive Components of the Integrated Stress Response  

Oleh:

Sikalidis, Angelos K. ; Stipanuk, Martha H.

Jenis: Article from Journal - ilmiah internasional
Dalam koleksi: JN: The Journal of Nutrition vol. 140 no. 06 (Jun. 2010), page 1080-1085.
Topik: SULFUR AMINO ACID; INTEGRATED STRESS RESPONSE

Ketersediaan

Perpustakaan FK Nomor Panggil: J42.K.2010.02 Non-tandon: 1 (dapat dipinjam: 0) Tandon: tidak ada

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Isi artikel

Mammalian cells respond to various kinds of stress, including nutritional stress, via pathways that are initiated by phosphorylation of the {alpha} subunit of the eukaryotic initiation factor 2 complex (eIF2{alpha}). Because the models used to study eIF2{alpha}-kinase–mediated responses to amino acid deficiency have commonly used media or diets devoid of 1 or more essential amino acids, we asked whether eIF2{alpha}-kinase–mediated responses would be induced in animals fed a more typical diet that was not as imbalanced as one in which 1 essential amino acid is totally absent. To answer this question, we fed rats soy protein-based diets that were either adequate or limiting in sulfur-containing amino acids (SAA). Rats fed a SAA-deficient diet (3.4 g methionine equivalents/kg diet) grew more slowly than rats fed the control diet (5.86 g methionine equivalents/kg diet). Analysis of liver from rats fed these diets for 7 d showed that the SAA-deficient rats had higher levels of eIF2{alpha} phosphorylation and higher levels of activating transcription factor (ATF) 4, ATF3, asparagine synthetase, solute carrier 7A11, cysteinyl-tRNA synthetase, and cystathionine {gamma}-lyase. On the other hand, components of the integrated stress response (ISR) known to promote apoptosis or translational recovery were not induced. Taken together, our results indicate that rats fed the SAA-deficient diet had a prolonged activation of an eIF2{alpha} kinase that leads to upregulation of adaptive components of the ISR.

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