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EIF4A
The eukaryotic initiation factor-4A (eIF4A) family consists of 3 closely related proteins EIF4A1, EIF4A2, and EIF4A3. These factors are required for the binding of Messenger RNA, mRNA to 40S ribosome, ribosomal subunits. In addition these proteins are helicases that function to unwind double-stranded RNA. Background The mechanisms governing the basic subsistence of Eukaryote, eukaryotic cells are immensely complex; it is therefore unsurprising that regulation occurs at a number of stages of protein synthesis – the regulation of translation has become a well-studied field. Human translational control is of increasing research interest as it has connotations in a range of diseases. Orthologs of many of the factors involved in human translation are shared by a range of eukaryotic organisms; some of which are used as Model organism, model systems for the investigation of translation initiation and elongation, for example: sea urchin eggs upon fertilization, rodent brain and rab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIF4A1
Eukaryotic initiation factor 4A-I (also known as eIF4A1 or DDX2A) is a 46 kDa cytosolic protein that, in humans, is encoded by the ''EIF4A1'' gene, which is located on chromosome 17. It is the most prevalent member of the eIF4A protein family, family of adenosine triphosphate, ATP-dependant RNA helicases, and plays a critical role in the initiation of cap-dependent Eukaryotic translation, eukaryotic protein translation as a component of the eIF4F translation initiation complex. eIF4A1 unwinds the secondary structure of RNA within the Five prime untranslated region, 5'-UTR of mRNA, a critical step necessary for the recruitment of the 43S preinitiation complex, and thus the translation of protein in eukaryotes. It was first characterized in 1982 by Grifo, ''et al.'', who purified it from rabbit reticulocyte lysate. Background The regulation of the Translation (biology), translation of mRNA transcripts into protein is one of the best ways that a cell can alter its response to its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIF4A3
Eukaryotic initiation factor 4A-III is a protein that in humans is encoded by the ''EIF4A3'' gene. Function This gene encodes a member of the DEAD box protein family. DEAD box proteins, characterized by the conserved motif Asp- Glu- Ala-Asp (DEAD), are putative RNA helicases. They are implicated in a number of cellular processes involving alteration of RNA secondary structure, such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly. Based on their distribution patterns, some members of this family are believed to be involved in embryogenesis, spermatogenesis, and cellular growth and division. The protein encoded by this gene is a nuclear matrix protein. Its amino acid sequence is highly similar to the amino acid sequences of the translation initiation factor Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. The English language draws a ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIF4F
Eukaryotic initiation factor 4F (eIF4F) is a heterotrimeric protein complex that binds the Five-prime cap, 5' cap of Messenger RNA, messenger RNAs (mRNAs) to promote eukaryotic translation initiation. The eIF4F complex is composed of three non-identical subunits: the DEAD box, DEAD-box RNA helicase eIF4A, the cap-binding protein eIF4E, and the large "scaffold" protein eIF4G. The mammalian eIF4F complex was first described in 1983, and has been a major area of study into the molecular mechanisms of cap-dependent translation initiation ever since. Function eIF4F is important for recruiting the Eukaryotic small ribosomal subunit (40S), small ribosomal subunit (40S) to the 5' cap of mRNAs during Eukaryotic translation#Cap-dependent initiation, cap-dependent translation initiation. Components of the complex are also involved in Eukaryotic translation#Cap-independent initiation, cap-independent translation initiation; for instance, certain viral proteases cleave eIF4G to remove the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DEAD Box
DEAD box proteins are involved in an assortment of metabolic processes that typically involve RNAs, but in some cases also other nucleic acids. They are highly conserved in nine motifs and can be found in most prokaryotes and eukaryotes, but not all. Many organisms, including humans, contain DEAD-box (SF2) helicases, which are involved in RNA metabolism. DEAD box family DEAD box proteins were first brought to attention in the late 1980s in a study that looked at a group of NTP binding sites that were similar in sequence to the eIF4A RNA helicase sequence. The results of this study showed that these proteins (p68, SrmB, MSS116, vasa, PL10, mammalian eIF4A, yeast eIF4A) involved in RNA metabolism had several common elements. There were nine common sequences found to be conserved amongst the studied species, which is an important criterion of the DEAD box family. The nine conserved motif from the N-terminal to the C-terminal are named as follows: Q-motif, motif 1, motif 1a, moti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIF4A2
Eukaryotic initiation factor 4A-II is a protein that in humans is encoded by the ''EIF4A2'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei .... References Further reading * * * * * * * * * * External links * {{gene-3-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIF4H
Eukaryotic translation initiation factor 4H is a protein that in humans is encoded by the ''EIF4H'' gene. This gene encodes one of the translation initiation factors, which function to stimulate the initiation of protein synthesis at the level of mRNA utilization. This gene is deleted in Williams syndrome, a multisystem developmental disorder caused by the deletion of contiguous genes at 7q11.23. Alternative splicing of this gene generates 2 transcript variants. EIF4H appears analogous to drr-2 in ''C. elegans'' which regulates the mTOR pathway The mammalian target of rapamycin (mTOR), also referred to as the mechanistic target of rapamycin, and sometimes called FK506-binding protein 12-rapamycin-associated protein 1 (FRAP1), is a kinase that in humans is encoded by the ''MTOR'' gene. ... and affects longevity. References Further reading * * * * * * * * * * * * * * * External links * {{protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIF4E
Eukaryotic translation initiation factor 4E, also known as eIF4E, is a protein in humans encoded by the ''EIF4E'' gene. eIF4E plays a central role in translation initiation and is involved in regulating protein synthesis. Its activity influences a range of biological processes and disease states, making it an important target for therapeutic development, particularly in disorders characterized by aberrant protein production. Discovery eIF4E was discovered as a cytoplasmic cap binding protein functioning in translation by Witold Filipowicz at al. In 1976. Two years later, in 1978, Sonenberg et al. confirmed Filipowicz et al.’s findings by repeating the same experiments and adding a crosslinking chemical to increase the stability of the mRNA-protein complex. This has been confirmed by numerous scientists in their published articles such as Katherine L. B. Borden, Michael J. Osborne and Katherine L.B. Borden. Structure Most eukaryote, eukaryotic cellular Messenger RNA, mRNAs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIF4B
Eukaryotic translation initiation factor 4B is a protein that in humans is encoded by the ''EIF4B'' gene. Interactions eIF4B has been shown to interact with and stimulate the activity of eIF4A and bind to the eIF3 complex through the eIF3A subunit. This interaction results in the recruitment of the eukaryotic small ribosomal subunit (40S) to the mRNA which will in turn set the stage for the later steps leading to elongation. See also *Eukaryotic translation *eIF4F Eukaryotic initiation factor 4F (eIF4F) is a heterotrimeric protein complex that binds the Five-prime cap, 5' cap of Messenger RNA, messenger RNAs (mRNAs) to promote eukaryotic translation initiation. The eIF4F complex is composed of three non-i ... References Further reading * * * * * * * * * * * * * * * * * * {{gene-12-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juri Rappsilber
Juri Rappsilber (born 1971) is a German chemist in the area of mass spectrometry and proteomics. Career Rappsilber studied chemistry at Technische Universität Berlin, University of Strathclyde, and with Tom Rapoport, Harvard Medical School. In 2001, he earned his Ph.D. in Proteomics jointly from EMBL Heidelberg and the Goethe University Frankfurt working in the laboratory of Matthias Mann on the mass spectrometric analysis of protein complexes, externally supervised by Michael Karas. He followed Mann to the University of Southern Denmark and completed a postdoctoral fellowship before starting his independent career at IFOM - FIRC Institute for Molecular Oncology, Milan in 2003. In 2006, he joined the Wellcome Trust Centre for Cell Biology in the Institute of Cell Biology at the University of Edinburgh. In 2009, he became a senior research fellow of the Wellcome Trust, in 2010 he was appointed Professor of Proteomics in Edinburgh. Since 2011, he has been Full Professor and he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Start Codon
The start codon is the first codon of a messenger RNA (mRNA) transcript translated by a ribosome. The start codon always codes for methionine in eukaryotes and archaea and a ''N''-formylmethionine (fMet) in bacteria, mitochondria and plastids. The start codon is often preceded by a 5' untranslated region (5' UTR). In prokaryotes this includes the ribosome binding site. Decoding In all three domains of life, the start codon is decoded by a special "initiation" transfer RNA different from the tRNAs used for elongation. There are important structural differences between an initiating tRNA and an elongating one, with distinguish features serving to satisfy the constraints of the translation system. In bacteria and organelles, an acceptor stem C1:A72 mismatch guide formylation, which directs recruitment by the 30S ribosome into the P site; so-called "3GC" base pairs allow assembly into the 70S ribosome. In eukaryotes and archaea, the T stem prevents the elongation factors from bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cereal Germ
The germ of a cereal grain is the part that develops into a plant; it is the seed embryo. Along with bran, germ is often a by-product of the milling that produces refined grain products. Cereal grains and their components, such as wheat germ oil, rice bran oil, and maize bran, may be used as a source from which vegetable oil is extracted, or used directly as a food ingredient. The germ is retained as an integral part of whole-grain foods. Non-whole grain methods of milling are intended to isolate the endosperm, which is ground into flour, with removal of both the husk (bran) and the germ. Removal of bran produces a flour with a white rather than a brown color and eliminates fiber. The germ is rich in polyunsaturated fats (which have a tendency to oxidize and become rancid on storage) and so germ removal improves the storage qualities of flour. Wheat germ Wheat germ or wheatgerm is a concentrated source of several essential nutrients, including vitamin E, folate (foli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIF3
Eukaryotic initiation factor 3 (eIF3) is a multiprotein complex that functions during the initiation phase of eukaryotic translation. It is essential for most forms of Eukaryotic translation#Cap-dependent initiation, cap-dependent and Eukaryotic translation#cap-independent, cap-independent translation initiation. In humans, eIF3 consists of 13 nonidentical subunits (eIF3a-m) with a combined molecular weight of ~800 kDa, making it the largest Eukaryotic initiation factor, translation initiation factor. The eIF3 complex is broadly conserved across eukaryotes, but the conservation of individual subunits varies across organisms. For instance, while most mammalian eIF3 complexes are composed of 13 subunits, Saccharomyces cerevisiae, budding yeast's eIF3 has only six subunits (eIF3a, b, c, g, i, j). Function eIF3 stimulates nearly all steps of translation initiation. eIF3 also appears to participate in other phases of translation, such as recycling, where it promotes the splitting of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
