WordNet

place signs, as along a road; "sign an intersection"; "This road has been signed"
(medicine) any objective evidence of the presence of a disorder or disease; "there were no signs of asphyxiation"
a perceptible indication of something not immediately apparent (as a visible clue that something has happened); "he showed signs of strain"; "they welcomed the signs of spring" (同)mark
a character indicating a relation between quantities; "dont forget the minus sign"
a fundamental linguistic unit linking a signifier to that which is signified; "The bond between the signifier and the signified is arbitrary"--de Saussure
a gesture that is part of a sign language
a public display of a message; "he posted signs in all the shop windows"
engage by written agreement; "They signed two new pitchers for the next season" (同)contract, sign on, sign_up
approve and express assent, responsibility, or obligation; "All parties ratified the peace treaty"; "Have you signed your contract yet?" (同)ratify
communicate silently and non-verbally by signals or signs; "He signed his disapproval with a dismissive hand gesture"; "The diner signaled the waiters to bring the menu" (同)signal, signalize, signalise
mark with ones signature; write ones name (on); "She signed the letter and sent it off"; "Please sign here" (同)subscribe
be engaged by a written agreement; "He signed to play the casino on Dec. 18"; "The soprano signed to sing the new opera"
communicate in sign language; "I dont know how to sign, so I could not communicate with my deaf cousin"
notably out of the ordinary; "the year saw one signal triumph for the Labour party"
an electric quantity (voltage or current or field strength) whose modulation represents coded information about the source from which it comes
any nonverbal action or gesture that encodes a message; "signals from the boat suddenly stopped" (同)signaling, sign
any incitement to action; "he awaited the signal to start"; "the victory was a signal for wild celebration"
amide combining the amino group of one amino acid with the carboxyl group of another; usually obtained by partial hydrolysis of protein

PrepTutorEJDIC

(ある事実・状態・感情などの)『表れ』,印,気配,徴侯(indication);(…の)こん跡,計跡《+『of』+『名』》・『身ぶり』,手まね,合図 / 『標識』,看板 / (数学・音楽などの)記号 / (…の)『象徴』,シンボル(symbol)《+『of』+『名』》・《文》(…の)『前兆』,きざし《+『of』+『名』》・宮(きゅう)(黄道12区分の一つ) ・〈手紙・書類・作品など〉‘に'『署名する』・(…に)〈名前など〉‘を'書く《+『名』+『on』(『to』)+『名』》 / …‘を'雇う契約に署名する・…‘を'合図する,知らせる;…に合図する・署名する・契約書に署名して雇われる
(警告・指示・情報などを伝える)『信号』,合図 / (…の)きっかけ,動機,導火線《+『for』+『名』》 / 〈人・車など〉‘に'『合図する』,信号を送る / …‘を'『合図』(信号)『で知らせる』 / 『合図する』,信号する / 合図の,信号の / めざましい,顕著な

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/02/20 09:44:12」(JST)

wiki en

A signal peptide (sometimes referred to as signal sequence, targeting signal, localization signal, localization sequence, transit peptide, leader sequence or leader peptide) is a short (5-30 amino acids long) peptide present at the N-terminus of the majority of newly synthesized proteins that are destined towards the secretory pathway.^[1] These proteins include those that reside either inside certain organelles (the endoplasmic reticulum, golgi or endosomes), secreted from the cell, or inserted into most cellular membranes. Although most type I membrane-bound proteins have signal peptides, the majority of type II and multi-spanning membrane-bound proteins are targeted to the secretory pathway by their first transmembrane domain, which biochemically resembles a signal sequence except that it is not cleaved.

Translocation

In prokaryotes, signal peptides direct the newly synthesized protein to the SecYEG protein-conducting channel, which is present in the plasma membrane. A homologous system exists in eukaryotes, where the signal peptide directs the newly synthesized protein to the Sec61 channel, which shares structural and sequence homology with SecYEG, but is present in the endoplasmic reticulum.^[2] Both the SecYEG and Sec61 channels are commonly referred to as the translocon, and transit through this channel is known as translocation. While secreted proteins are threaded through the channel, transmembrane domains may diffuse across a lateral gate in the translocon to partition into the surrounding membrane.

Signal peptide structure

The core of the signal peptide contains a long stretch of hydrophobic amino acids (about 5-16 residues long)^[3] that has a tendency to form a single alpha-helix and is also referred to as the "h-region". In addition, many signal peptides begin with a short positively charged stretch of amino acids, which may help to enforce proper topology of the polypeptide during translocation by what is known as the positive-inside rule.^[4] Because of its close location to the N-terminus it is called the "n-region". At the end of the signal peptide there is typically a stretch of amino acids that is recognized and cleaved by signal peptidase and therefore named cleavage site. However this cleavage site is absent from transmembrane-domains that serve as signal peptides, which are sometimes referred to as signal anchor sequences. Signal peptidase may cleave either during or after completion of translocation to generate a free signal peptide and a mature protein. The free signal peptides are then digested by specific proteases.

Co-translational versus post-translational translocation

In both prokaryotes and eukaryotes signal sequences may act co-translationally or post-translationally.

The co-translational pathway is initiated when the signal peptide emerges from the ribosome and is recognized by the signal-recognition particle (SRP).^[5] SRP then halts further translation and directs the signal sequence-ribosome-mRNA complex to the SRP receptor, which is present on the surface of either the plasma membrane (in prokaryotes) or the ER (in eukaryotes).^[6] Once membrane-targeting is completed, the signal sequence is inserted into the translocon. Ribosomes are then physically docked onto the cytoplasmic face of the translocon and protein synthesis resumes.^[7]

The post-translational pathway is initiated after protein synthesis is completed. In prokaryotes, the signal sequence of post-translational substrates is recognized by the SecB chaperone protein that transfers the protein to the SecA ATPase, which in turn pumps the protein through the translocon. Although post-translational translocation is known to occur in eukaryotes, it is poorly understood. It is however known that in yeast post-translational translocation requires the translocon and two additional membrane-bound proteins, Sec62 and Sec63.^[8]

Signal peptides determine secretion efficiency

Signal peptides are extremely heterogeneous and many prokaryotic and eukaryotic signal peptides are functionally interchangeable even between different species however the efficiency of protein secretion is strongly determined by the signal peptide.^[9]^[10]

Nucleotide level features

In vertebrates, the region of the mRNA that codes for the signal peptide (i.e. the signal sequence coding region, or SSCR) can function as an RNA element with specific activities. SSCRs promote nuclear mRNA export and the proper localization to the surface of the endoplasmic reticulum. In addition SSCRs have specific sequence features: they have low adenine-content, are enriched in certain motifs, and tend to be present in the first exon at a frequency that is higher than expected.^[11]^[12]

Signal peptide less secretion

Proteins without signal peptides can also be secreted by unconventional mechanisms. E.g. Interleukin, Galectin.^[13] The process by which such secretory proteins gain access to the cell exterior is termed unconventional protein secretion (UPS). In plants, even 50% of secreted proteins can be UPS dependent.^[14]

References

^ Blobel G, Dobberstein B (Dec 1975). "Transfer of proteins across membranes. I. Presence of proteolytically processed and unprocessed nascent immunoglobulin light chains on membrane-bound ribosomes of murine myeloma.". J Cell Bio. 67 (3): 835–51. doi:10.1083/jcb.67.3.835. PMC 2111658. PMID 811671.
^ Rapoport T. (Nov 2007). "Protein translocation across the eukaryotic endoplasmic reticulum and bacterial plasma membranes.". Nature. 450 (7170): 663–9. doi:10.1038/nature06384. PMID 18046402.
^ Käll, Lukas; Krogh, Anders; Sonnhammer, Erik L. L. (2004). "A Combined Transmembrane Topology and Signal Peptide Prediction Method". J. Mol. Biol. 338: 1027–1036. doi:10.1016/j.jmb.2004.03.016.
^ von Heijne, G.; Gavel, Y. (Jul 1988). "Topogenic signals in integral membrane proteins". Eur J Biochem. 174 (4): 671–8. doi:10.1111/j.1432-1033.1988.tb14150.x. PMID 3134198.
^ Walter P, Ibrahimi I, Blobel G (Nov 1981). "Translocation of proteins across the endoplasmic reticulum. I. Signal recognition protein (SRP) binds to in-vitro-assembled polysomes synthesizing secretory protein". JCB. 91 (2 Pt1): 545–50. doi:10.1083/jcb.91.2.545. PMC 2111968. PMID 7309795.
^ Gilmore R, Blobel G, Walter P (Nov 1982). "Protein translocation across the endoplasmic reticulum. I. Detection in the microsomal membrane of a receptor for the signal recognition particle". JCB. 95 (2 Pt1): 463–9. doi:10.1083/jcb.95.2.463. PMC 2112970. PMID 6292235.
^ Görlich D, Prehn S, Hartmann E, Kalies KU, Rapoport TA (Oct 1992). "A mammalian homolog of SEC61p and SECYp is associated with ribosomes and nascent polypeptides during translocation". Cell. 71 (3): 489–503. doi:10.1016/0092-8674(92)90517-G. PMID 1423609.
^ Panzner, S; Dreier, L; Hartmann, E; Kostka, S; Rapoport, TA (1995). "Posttranslational protein transport in yeast reconstituted with a purified complex of Sec proteins and Kar2p". Cell. 81 (4): 561–570. doi:10.1016/0092-8674(95)90077-2. ISSN 0092-8674. PMID 7758110.
^ Kober L, Zehe C, Bode J (April 2013). "Optimized signal peptides for the development of high expressing CHO cell lines". Biotechnol. Bioeng. 110 (4): 1164–73. doi:10.1002/bit.24776. PMID 23124363.
^ von Heijne G (Jul 1985). "Signal sequences: The limits of variation". J Mol Biol. 184 (1): 99–105. doi:10.1016/0022-2836(85)90046-4. PMID 4032478.
^ Palazzo, Alexander F.; Springer, Michael; Shibata, Yoko; Lee, Chung-Sheng; Dias, Anusha P.; Rapoport, Tom A. (2007). "The Signal Sequence Coding Region Promotes Nuclear Export of mRNA". PLoS Biology. 5 (12): e322. doi:10.1371/journal.pbio.0050322. ISSN 1544-9173. PMC 2100149. PMID 18052610.
^ Cenik, Can; Chua, Hon Nian; Zhang, Hui; Tarnawsky, Stefan P.; Akef, Abdalla; Derti, Adnan; Tasan, Murat; Moore, Melissa J.; Palazzo, Alexander F.; Roth, Frederick P. (2011). Snyder, Michael, ed. "Genome Analysis Reveals Interplay between 5′UTR Introns and Nuclear mRNA Export for Secretory and Mitochondrial Genes". PLoS Genetics. 7 (4): e1001366. doi:10.1371/journal.pgen.1001366. ISSN 1553-7404. PMC 3077370. PMID 21533221.
^ Nickel, W; Seedorf, M (2008). "Unconventional mechanisms of protein transport to the cell surface of eukaryotic cells.". Annual Review of Cell and Developmental Biology. 24: 287–308. doi:10.1146/annurev.cellbio.24.110707.175320. PMID 18590485.
^ Agrawal, GK; Jwa, NS; Lebrun, MH; Job, D; Rakwal, R (February 2010). "Plant secretome: unlocking secrets of the secreted proteins.". Proteomics. 10 (4): 799–827. doi:10.1002/pmic.200900514. PMID 19953550.

External links

Signal Peptide at the US National Library of Medicine Medical Subject Headings (MeSH)
SPdb (Signal Peptide DataBase)
SignalP — predicts the presence and location of signal peptide cleavage sites in amino acid sequences from different organisms.

UpToDate Contents

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1. ペプチドホルモンのシグナル伝達および調節 peptide hormone signal transduction and regulation
2. 血管作動性腸管ポリペプチド vasoactive intestinal polypeptide
3. 心不全におけるナトリウム利尿ペプチド測定 natriuretic peptide measurement in heart failure
4. 膵ポリペプチド、ペプチドYY、およびニューロペプチドY pancreatic polypeptide peptide yy and neuropeptide y
5. インスリン受容体の構造および機能 structure and function of the insulin receptor

English Journal

Retracted article: Quantum dots high fluorescent signal amplification immunoassay using branched DNA and peptide nucleic acid conjugated antibody.

Cao YC, Ali S, Hanley QS, Boocock D, Matharoo-Ball B.SourceSchool of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK. yuancheng.cao@gmail.com quentin.hanley@ntu.ac.uk.
The Analyst.Analyst.2012 Dec 16. [Epub ahead of print]
I, Yuan-Cheng Cao, hereby wholly retract this Analyst paper for correction. This article was submitted for publication without the knowledge and approval of the co-authors listed. Signed: Yuan-Cheng Cao, Newcastle University, UK, December 2011. This retraction is endorsed by May Copsey, Editor. Retr
PMID 22016880

Increasing the range of drug targets: Interacting peptides provide leads for the development of oncoprotein inhibitors.

Groner B, Weber A, Mack L.SourceGeorg Speyer Haus; Institute for Biomedical Research; Frankfurt am Main, Germany.
Bioengineered.Bioengineered.2012 Nov 1;3(6). [Epub ahead of print]
Two limiting aspects are mainly responsible for the sluggish development of new cancer drugs. They concern the chemical properties of potential drug molecules and the structural prerequisites for drug targets. The chemical properties which are being considered desirable for potential drugs are rathe
PMID 22825353

Japanese Journal

Label-Free Analysis of O-glycosylation Site-Occupancy Based on the Signal Intensity of Glycopeptide/Peptide Ions (Mass Spectrometry) -- (Special Issue : Professor Hisashi Matsuda Memorial Issue)

Wada Yoshinao
Journal of the Mass Spectrometry Society of Japan = 質量分析 60(6), 1-5, 2012-12
NAID 40019515371

cDNA cloning and bacterial expression of a PL-14 alginate lyase from a herbivorous marine snail Littorina brevicula

Rahman Mohammad Matiur,Wang Ling,Inoue Akira,Ojima Takao
Carbohydrate Research 360, 69-77, 2012-10-01
… The deduced amino-acid sequence comprised an initiation methionine, a putative signal peptide of 14 residues, a propeptide-like region of 16 residues, and a mature LbAly28 domain of 260 residues. …
NAID 120004857012

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★リンクテーブル★

リンク元	「シグナル配列」「presequence」「protein sorting signal」「leader peptide」「シグナルペプチド」
関連記事	「sign」「signaling」「signal」