70:
225:
which is bound to the ribosomal exit tunnel and initiates recognition and shielding as protein is translated. The second strategy involves tail-anchored proteins, defined by a single TMD located close to the carboxyl terminus of the membrane protein. Once translation is completed, the tail-anchored
114:
Mediating transport and sorting of transmembrane proteins; TMDs have been shown to work in tandem with cytosolic sorting signals, with length and hydrophobicity being the main determinants in TDM sorting. Longer and more hydrophobic TMDs aid in sorting proteins to the cell membrane, whereas shorter
226:
TMD remains in the ribosomal exit tunnel, and an ATPase mediates targeting to the endoplasmic reticulum. Examples of shuttling factors include TRC40 in higher eukaryotes and Get3 in yeast. Furthermore, general TMD-binding factors protect against aggregation and other disrupting interactions.
208:
or other organelles) are also required. Factors also detect TMD misfolding within the membrane and perform quality control functions. These factors must be able to recognize a highly variable set of TMDs and can be segregated into those active in the cytosol or active in the membrane.
257:
membrane. Quality control factors must be able to discern function and topology, as well as facilitate extraction to the cytosol. The signal recognition particle transports membrane proteins to the Sec
204:
environment), factors that recognize the TMD and protect them in this hostile environment are required. Additional factors that allow the TMD to be incorporated into the target membrane (i.e.
565:
Devoto A, Hartmann HA, Piffanelli P, Elliott C, Simmons C, Taramino G, et al. (January 2003). "Molecular phylogeny and evolution of the plant-specific seven-transmembrane MLO family".
111:; the function of TMDs is not well understood, but they have been shown to be critical for the fusion reaction, possibly as a result of TMDs affecting the tension of the lipid bilayer.
217:
Cytosolic recognition factors are thought to use two distinct strategies. In the co-translational strategy the recognition and shielding are coupled to protein synthesis.
466:
Krogh A, Larsson B, von Heijne G, Sonnhammer EL (January 2001). "Predicting transmembrane protein topology with a hidden Markov model: application to complete genomes".
167:
of a protein; i.e. prediction of what parts of it protrude into the cell, what parts protrude out, and how many times the protein chain crosses the membrane.
234:
are two well-known general TMD-binding factors. Quality control of membrane proteins involve TMD-binding factors that are linked to
104:, receive extracellular signals. TMDs then propagate those signals across the membrane to induce an intracellular effect.
148:, it is presumed to be a requirement of the amino acids that span a membrane that they be hydrophobic as well. However,
627:
622:
266:
central pore and minimizing exposure of the TMD to cytosol. Insertases can also mediate TMD insertion into the
218:
222:
156:
also contain numerous charged and polar residues within the generally non-polar transmembrane segments.
325:
Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Raff, Martin; Roberts, Keith; Walter, Peter (2002).
101:
300:
270:. Insertases include the bacterial YidC, mitochondrial Oxa1, and chloroplast Alb3, all of which are
221:
indicate the majority of membrane proteins targeting the endoplasmic reticulum are handled by the
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193:
137:
133:
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64:
48:
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8:
510:"Transmembrane Domain Recognition during Membrane Protein Biogenesis and Quality Control"
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411:"Anchors aweigh: protein localization and transport mediated by transmembrane domains"
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Transmembrane helices are visible in structures of membrane proteins determined by
40:
39:, the amino acid residues in TMDs are often hydrophobic, although proteins such as
94:; usually hydrophilic residues and binding sites in the TMDs help in this process.
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Transmembrane domains are known to perform a variety of functions. These include:
120:
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97:
24:
586:
526:
509:
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361:
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369:
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141:
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28:
345:
307:) proteins have 7 conserved transmembrane domains that encode alpha helices.
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enzyme families are examples of membrane bound quality control factors.
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Once transported, factors assist with insertion of the TMD across the
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to predict transmembrane helices enables a prediction in turn of the
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The role of membrane protein biogenesis and quality control factors
409:
Cosson, Pierre; Perrin, Jackie; Bonifacino, Juan S. (2013-10-01).
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87:
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115:
and less hydrophobic TMDs are used to retain proteins in the
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and the interiors of most proteins of known structure are
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across the membrane; many transmembrane proteins, such as
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can contain polar residues. TMDs vary greatly in size and
83:
343:
344:
Langosch, D.; Hofmann, M.; Ungermann, C. (April 2007).
324:
262:, positioning the ribosome exit tunnel proximal to the
123:. The exact mechanism of this process is still unknown.
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346:"The role of transmembrane domains in membrane fusion"
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Facilitating molecular transport of molecules such as
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anchored to the membrane by its transmembrane domain.
54:
614:
212:
51:; they may adopt organelle-specific properties.
508:Guna, Alina; Hegde, Ramanujan S. (2018-04-23).
244:
35:. Because the interior of the lipid bilayer is
170:Transmembrane helices can also be identified
136:. They may also be predicted on the basis of
331:Molecular Biology of the Cell. 4th Edition
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68:
297:have 4 conserved transmembrane domains.
128:Identification of transmembrane helices
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27:. TMDs may consist of one or several
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350:Cellular and Molecular Life Sciences
253:layer phosphate "head" group of the
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55:Functions of transmembrane domains
14:
639:
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16:Membrane-spanning protein domain
219:Genome wide association studies
567:Journal of Molecular Evolution
558:
459:
402:
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140:. Because the interior of the
1:
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213:Cytosolic Recognition Factors
468:Journal of Molecular Biology
245:Membrane Recognition Factors
7:
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223:signal recognition particle
102:G protein-coupled receptors
10:
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21:transmembrane domain (TMD)
628:Protein structural motifs
587:10.1007/s00239-002-2382-5
527:10.1016/j.cub.2018.02.004
427:10.1016/j.tcb.2013.05.005
362:10.1007/s00018-007-6439-x
161:"hydrophobicity analysis"
165:"transmembrane topology"
23:is a membrane-spanning
623:Transmembrane proteins
480:10.1006/jmbi.2000.4315
415:Trends in Cell Biology
78:
65:transmembrane proteins
260:translocation channel
206:endoplasmic reticulum
138:hydrophobicity scales
117:endoplasmic reticulum
72:
92:biological membranes
579:2003JMolE..56...77D
327:"Membrane Proteins"
98:Signal transduction
31:or a transmembrane
79:
134:X-ray diffraction
67:to the membrane.
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520:(8): R498–R511.
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356:(7–8): 850–864.
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514:Current Biology
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421:(10): 511–517.
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121:Golgi apparatus
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301:Mildew locus o
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272:evolutionarily
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236:ubiquitination
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196:occurs in the
192:Since protein
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150:membrane pumps
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109:vesicle fusion
105:
95:
80:
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49:hydrophobicity
41:membrane pumps
25:protein domain
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474:(3): 567–80.
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274:related. The
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268:lipid bilayer
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178:bioinformatic
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107:Assisting in
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75:AMPA receptor
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29:alpha-helices
26:
22:
573:(1): 77–88.
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471:
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418:
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295:Tetraspanins
255:phospholipid
248:
216:
191:
171:
169:
158:
154:ion channels
131:
58:
45:ion channels
20:
18:
251:hydrophilic
194:translation
146:hydrophobic
37:hydrophobic
33:beta barrel
617:Categories
312:References
264:translocon
239:proteasome
232:calmodulin
176:using the
63:Anchoring
536:1879-0445
435:0962-8924
370:1420-682X
276:conserved
173:in silico
603:25514671
595:12569425
552:13839449
544:29689233
488:11152613
453:23806646
396:23714815
388:17429580
379:11136198
289:Examples
241:system.
119:and the
88:proteins
575:Bibcode
444:3783643
202:aqueous
198:cytosol
142:bilayer
90:across
601:
593:
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486:
451:
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386:
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283:Derlin
180:tool,
159:Using
599:S2CID
548:S2CID
392:S2CID
182:TMHMM
591:PMID
540:PMID
532:ISSN
484:PMID
449:PMID
431:ISSN
384:PMID
366:ISSN
281:and
279:Hrd1
230:and
228:SGTA
200:(an
152:and
86:and
84:ions
43:and
583:doi
522:doi
476:doi
472:305
439:PMC
423:doi
374:PMC
358:doi
305:mlo
73:An
619::
597:.
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571:56
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518:28
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512:.
496:^
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184:.
19:A
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333:.
303:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
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