Abstract: Ribosome is the unique area for protein synthesis and mainly consists of RNA(rRNA) as well as dozens of different r-proteins. R-proteins and rRNA form two different sizes of subunit. Small subunit binds with mRNA and large subunit respectively to form the complete ribosome. The two subunits convert mRNA into polypeptide chain together.
Keywords: Protein Synthesis, Ribosome Protein, Ribosome Marker
1. About Ribosome
The structure of ribosome is different from other organelles, such as uncoated membrane, two subunits, attached to endoplasmic reticulum or free from cytoplasm. Thus, ribosome is also considered as intracellular macromolecule instead of organelle.
2. Ribosomes in Prokaryotes and Eukaryotes
Prokaryotes only have one ribosome. Two kinds of ribosomes are in mammalian cells. Cytoplasm ribosomes and ribosomes located in mitochondria are called mitoribosomes. Pharmaceutical chemist produces protein synthesis inhibitor antibiotics (e.g. aminoglycoside or tetracycline antibiotics etc.) to specifically disrupt bacterial infection through differences of bacteria and eukaryotic ribosomes. Due to different structures, bacterial 70S ribosome is easily affected by these antibiotics. Although mitochondria have the ribosome similar to bacteria, they are not affected by these antibiotics. Since they are surrounded by dual membranes, antibiotics are difficult to enter into organelle.
3. Ribosome Location
Ribosomes can be divided into free and membrane-bound ribosomes according to the binding with membrane.
3.1. Free Ribosomes
Free ribosomes can move in the any area of cytoplasm but are excluded from nucleus and other organelles. Proteins produced by free ribosomes are released into cytoplasm and used in cells. Cytoplasm contains high concentration of glutathione and belongs to the reduction environment. Thus, free ribosomes in the cytoplasm can't produce disulfide bond-containing protein formed by oxidized cysteine residues.
3.2. Membrane-bound Ribosomes
When ribosomes begin to synthesize proteins required by some organelles, ribosomes can bind with membranes. The binding in the eucaryotic cell occurs at rough endoplasmic reticulum(ER). Ribosomes insert the newly born polypeptide chain into ER directly. These polypeptide chains are transported to the destination through secretory pathway. Proteins produced by membrane-bound ribosomes are usually used in ER or excluded from cells through exocytosis.
4. Protein Synthesis in Ribosome
The biogenesis and protein synthesis of ribosome is the basic rate-limiting step of cell growth and proliferation. R-proteins(RP) containing ribosome structures is required by assembly and function of ribosome. Many RP have typical ribosome functions and extraribosomal functions (e.g. activation of p53 dependant or independent pathway in stress reaction), resulting in cell cycle arrest and apoptosis. Ribosome biogenesis, translation and deficiency of single RP(e.g. mutation in RP) are related to many ribosome diseases like human congenital diseases.
5. Recommended Products
Ribosome markers are ribosome proteins, e.g. RPS3-RPS6, RPL7A etc. Recommended antibodies and proteins are listed below respectively.
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Catalogue No. |
Antibody Name |
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anti- RPL7A antibody |
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anti- RPS3 antibody |
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anti- RPS3 antibody |
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anti- RPS3 antibody |
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anti- RPS5 antibody |
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anti- RPS6 antibody |
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anti- RPL4 antibody |
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anti- RPL23 antibody |
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anti- RPL18A antibody |
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anti- RPL18A antibody |
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anti- RPL11 antibody |
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anti- RPL10 antibody |
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Catalogue No. |
Protein Name |
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Recombinant Human RPL7A |
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Recombinant Human RPS3 |
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Recombinant Human RPS3 |
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Recombinant Human RPS5 |
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Recombinant Human RPS5 |
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Recombinant Human RPS4 |
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Recombinant Human RPL26 |
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Recombinant Human RPL23 |
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Recombinant Human RPL11 |
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Recombinant Human RPL11 |
REFERENCES
[1] EXOSC8 promotes colorectal cancer tumorigenesis via regulating ribosome biogenesis-related processes, PMID: 36348012.
[2] Low level of Fibrillarin, a ribosome biogenesis factor, is a new independent marker of poor outcome in breast cancer, PMID: 35545761.