Editing Topogenic sequence

A '''topogenic sequence''' is a collective term used for a [[peptide sequence]] present at nascent proteins essential for their insertion and orienting in [[cell membrane|cellular membranes]]. The sequences are also used to translocate proteins across various intracellular membranes,<ref name="robinson_role">{{cite journal|last=Robinson|first=A|date=1 September 1987|title=The role of topogenic sequences in the movement of proteins through membranes.|journal=Biochem. J.|volume=246|issue=2|pages=249–261|author2=Austen, B|doi=10.1042/bj2460249|pmid=3318806|pmc=1148271}}</ref> and ensure they are transported to the correct organelle after synthesis.<ref name="gould_plastid">{{cite journal|last=Gould|first=Sven|date=June 2008|title=Plastid Evolution|journal=Annual Review of Plant Biology|volume=59|pages=491–517|doi=10.1146/annurev.arplant.59.032607.092915|pmid=18315522|author2=Waller, R|author3=McFadden, G}}</ref> The position of the sequence may be at the end, e.g. N-terminal signal sequence, or in mid parts of the nascent protein, e.g. stop-transfer anchor sequences and signal-anchor sequences.<ref>{{Cite book|title=Molecular Cell Biology|last=Lodish|first=Harvey|publisher=Macmillan Higher Education|year=2013|isbn=978-1-4292-3413-9|location=|pages=587–588}}</ref> If the sequence is at the end of the polypeptide, it is cleaved off after entering the ER-lumen (via a translocon) by a signal peptidase, and subsequently degraded.

As an example, the vast majority of all known complex plastid [[preproteins]] (an 'unactivated' protein) encoded in the nucleus possess a topogenic sequence.<ref name=gould_plastid />

==See also==
* [[Protein targeting]]
* [[Target peptide]]
* [[Translocon]]
* [[Signal peptide]]

==References==
{{Reflist}}

{{DEFAULTSORT:Topogenic Sequence}}
[[Category:Peptide sequences]]


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