PubMed Health⌕ Search

PubMed · 14068231

RATIONALE FOR A UNIVERSAL GENETIC CODE.

Abstract

A mutation in the genetic code would place new amino acids in certain loci and entirely eliminate amino acids from other loci of practically all proteins in an organism. It is reasonable to postulate that mutations of this kind cannot supplant the original code. The genetic code, once established, would therefore remain invariant.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R T HINEGARDNER, J ENGELBERG. 1963-11-22. RATIONALE FOR A UNIVERSAL GENETIC CODE.. https://doi.org/10.1126/science.142.3595.1083

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Chimeric structural isomer fragments as cost-efficient internal standards for amino acid quantification by mass spectrometry.

Amino acid (AA) profiles from body fluids such as blood and urine are clinical indicators for diagnosing metabolic and hepatic diseases. Current quantitative methods, such as liquid chromatography-mass spectrometry (LC-MS) with isotopically labelled internal standards (ISs), are costly and technically demanding. This study proposes a cost-efficient alternative using structural isomers as ISs in a direct liquid infusion (DLI) tandem mass spectrometry (MS/MS) approach. The method leverages chimeric spectra and fragment intensity ratios to quantify AAs, demonstrating high linearity and precision even with a 3D ion trap mass analyser. This approach offers a viable strategy for AA quantification in preventive medicine, particularly for screening metabolic diseases such as phenylketonuria, diabetes, and liver dysfunction.

Amino Acids↗

Regulation of the small GTPase Rheb by amino acids.

The mTOR/S6K/4E-BP1 pathway integrates extracellular signals derived from growth factors, and intracellular signals, determined by the availability of nutrients like amino acids and glucose. Activation of this pathway requires inhibition of the tumor suppressor complex TSC1/2. TSC2 is a GTPase-activating protein for the small GTPase Ras homologue enriched in brain (Rheb), GTP loading of which activates mTOR by a yet unidentified mechanism. The level at which this pathway senses the availability of amino acids is unknown but is suggested to be at the level of TSC2. Here, we show that amino-acid depletion completely blocks insulin- and TPA-induced Rheb activation. This indicates that amino-acid sensing occurs upstream of Rheb. Despite this, amino-acid depletion can still inhibit mTOR/S6 kinase signaling in TSC2-/- fibroblasts. Since under these conditions Rheb-GTP levels remain high, a second level of amino-acid sensing exists, affecting mTOR activity in a Rheb-independent fashion.

Amino Acids↗

Chemokines in tumor immunotherapy.

The chemokines are a family of small molecules that mediate cell migration, activation, differentiation, angiogenesis, and perhaps other functions. The chemokines have been classified by their amino acid composition, functional activity, and receptor binding properties. The chemokines receptors are 7 transmembrane G proteins and there is considerable redundancy in ligand specificity. The role of chemokines in cancer is not well understood, but there is accumulating evidence that they play a major role in both tumorigenesis and the host immune response to tumors. Thus, chemokines and their receptors represent potential therapeutic targets for drug development. This article will briefly review the current understanding of chemokines biology of defined chemokines that are thought to be involved in tumor growth, metastasis, and the host immune response against cancer.

Amino Acids↗