Critically elucidating the role of selenium
Thus, Sec t RNA would be expected to decode the Sec codon, UGA, and the cysteine (Cys) codons, UCU/UCC. Beck and collaborators have provided a mouse model for Keshan disease wherein mice maintained on a Se sufficient diet and infected with coxsackie B3 virus were not affected and the virus remained non-virulent (see review in ).
The subsequent misreading of the Cys codons inserting Sec would most certainly be deleterious to cellular function. This is regarded as a highly specialized step in that its addition is dependent on the correct primary, secondary and tertiary structure of the t RNA . However, if the mice were maintained on a Se deficient diet and infected with the virus, the virus becomes virulent and the mice develop a cardiomyopathy. Targeted disruption of the type 2 selenodeiodinase gene (DIO2) results in a phenotype of pituitary resistance to T4.
The synthesis of selenoproteins is dependent on Sec t RNA for insertion of Sec, the 21 amino acid in the genetic code, into protein. Methylation of the ribosyl moiety at position 34 of selenocysteine t RNA[Ser]Sec is governed by both primary and tertiary structure.
The synthesis of selenoproteins is dependent on Sec t RNA for insertion of Sec, the 21st amino acid in the genetic code, into protein. One of the unique properties of selenoproteins is that their synthesis is dependent on Sec t RNA and, if the expression of this t RNA is altered, then the expression of the resulting class of selenoproteins is altered [9,10]. Selenium (Se) deficiency has been known for many years to be associated with disease, impaired growth and a variety of other metabolic disorders in mammals. Se is incorporated into selenocysteine (Sec) in the biosynthesis of this amino acid that constitutes the 21 , and the biosynthetic pathway of Sec was only recently established in eukaryotes and archaea [6,7]. Only recently has the major role that Se-containing proteins, designated selenoproteins, play in many aspects of health and development begun to emerge. Once Sec is biosynthesized on its t RNA, this amino acid is co-translationally inserted into protein. This cookie stores just a session ID; no other information is captured.Accepting the NEJM cookie is necessary to use the website.