News tagged with protein synthesis

Related topics: rna molecules · protein · gene expression · amino acids · messenger rna

How do neural cells respond to ischemia?

A group of researchers from the Lomonosov Moscow State University, in collaboration with their Irish colleagues from the University College Cork, has studied the early response of cells to ischemia, which is a restriction ...

May 06, 2015
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Finding the body clock's molecular reset button

An international team of scientists has discovered what amounts to a molecular reset button for our internal body clock. Their findings reveal a potential target to treat a range of disorders, from sleep disturbances to other ...

Apr 27, 2015
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Team identifies oncogene regulated by nutrients

Scientists from the Growth Factors, Nutrients and Cancer Group at the Spanish National Cancer Research Center (CNIO), led by Nabil Djouder, have discovered that the MCRS1 protein, in response to an excess of nutrients, induces ...

Apr 13, 2015
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Leukemia like Achilles, has its own weakness

Leukemia cells from chronic myeloid leukemia patients, especially those in the advanced stage, lack the BRCA1 protein. Importantly, the protein is not present even if the patient carries the proper, unmutated gene responsible ...

Mar 26, 2015
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Stress granules ease the way for cancer metastasis

Tumors that produce more stress granules are more likely to metastasize, according to a study published in The Journal of Cell Biology. The results suggest that drugs to inhibit the formation of these structures might rein ...

Mar 23, 2015
popularity10 comments 0

Protein biosynthesis

Protein synthesis is the process in which cells build proteins. The term is sometimes used to refer only to protein translation but more often it refers to a multi-step process, beginning with amino acid synthesis and transcription of nuclear DNA into messenger RNA which is then used as input to translation.

The cistron DNA is transcribed into a variety of RNA intermediates. The last version is used as a template in synthesis of a polypeptide chain. Proteins can often be synthesized directly from genes by translating mRNA. When a protein is harmful and needs to be available on short notice or in large quantities, a protein precursor is produced. A proprotein is an inactive protein containing one or more inhibitory peptides that can be activated when the inhibitory sequence is removed by proteolysis during posttranslational modification. A preprotein is a form that contains a signal sequence (an N-terminal signal peptide) that specifies its insertion into or through membranes; i.e., targets them for secretion. The signal peptide is cleaved off in the endoplasmic reticulum.. Preproproteins have both sequences (inhibitory and signal) still present.

For synthesis of protein, a succession of tRNA molecules charged with appropriate amino acids have to be brought together with an mRNA molecule and matched up by base-pairing through their anti-codons with each of its successive codons. The amino acids then have to be linked together to extend the growing protein chain, and the tRNAs, relieved of their burdens, have to be released. This whole complex of processes is carried out by a giant multimolecular machine, the ribosome, formed of two main chains of RNA, called ribosomal RNA (rRNA), and more than 50 different proteins. This molecular juggernaut latches onto the end of an mRNA molecule and then trundles along it, capturing loaded tRNA molecules and stitching together the amino acids they carry to form a new protein chain.

Protein biosynthesis, although very similar, is different for prokaryotes and eukaryotes.

This text uses material from Wikipedia, licensed under CC BY-SA

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