CHRNE
{{Short description|Protein-coding gene}}
{{cs1 config|name-list-style=vanc}}
{{Infobox_gene}}
Acetylcholine receptor subunit epsilon is a protein that in humans is encoded by the CHRNE gene.{{cite journal | vauthors = Beeson D, Brydson M, Betty M, Jeremiah S, Povey S, Vincent A, Newsom-Davis J | title = Primary structure of the human muscle acetylcholine receptor. cDNA cloning of the gamma and epsilon subunits | journal = Eur J Biochem | volume = 215 | issue = 2 | pages = 229–38 |date=Sep 1993 | pmid = 7688301 | doi =10.1111/j.1432-1033.1993.tb18027.x }}{{cite web | title = Entrez Gene: CHRNE cholinergic receptor, nicotinic, epsilon| url = https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1145}}
Acetylcholine receptors at mature mammalian neuromuscular junctions are pentameric protein complexes composed of four subunits in the ratio of two alpha subunits to one beta, one epsilon, and one delta subunit. The acetylcholine receptor changes subunit composition shortly after birth when the epsilon subunit replaces the gamma subunit seen in embryonic receptors. Mutations in the epsilon subunit are associated with congenital myasthenic syndrome.
Role in health and disease
Congenital myasthenic syndrome (CMS) is associated with genetic defects that affect proteins of the neuromuscular junction. Postsynaptic defects are the most frequent cause of CMS and often result in abnormalities in the acetylcholine receptor (AChR). The majority of mutations causing CMS are found in the AChR subunits genes.{{cite journal|last1=Cossins|first1=J.|last2=Burke|first2=G.|last3=Maxwell|first3=S.|last4=Spearman|first4=H.|last5=Man|first5=S.|last6=Kuks|first6=J.|last7=Vincent|first7=A.|last8=Palace|first8=J.|last9=Fuhrer|first9=C.|year=2006|title=Diverse molecular mechanisms involved in AChR deficiency due to rapsyn mutations|url=http://www.zora.uzh.ch/id/eprint/115/1/Cossins_2006.pdf|journal=Brain|volume=129|issue=10|pages=2773–2783|doi=10.1093/brain/awl219|pmid=16945936|last10=Beeson|first10=D.|doi-access=free|access-date=2019-04-11|archive-date=2018-11-04|archive-url=https://web.archive.org/web/20181104060834/https://www.zora.uzh.ch/id/eprint/115/1/Cossins_2006.pdf|url-status=dead}}
Out of all mutations associated with CMS, more than half are mutations in one of the four genes encoding the adult AChR subunits. Mutations of the AChR often result in endplate deficiency. The most common AChR gene mutation that underlies CMS is the mutation of the CHRNE gene. The CHRNE gene codes for the epsilon subunit of the AChR. Most mutations are autosomal recessive loss-of-function mutations and as a result there is endplate AChR deficiency. CHRNE is associated with changing the kinetic properties of the AChR.{{cite journal
| last1 = Abicht | first1 = A.
| last2 = Dusl | first2 = M.
| last3 = Gallenmüller | first3 = C.
| last4 = Guergueltcheva | first4 = V.
| last5 = Schara | first5 = U.
| last6 = Della Marina | first6 = A.
| last7 = Wibbeler | first7 = E.
| last8 = Almaras | first8 = S.
| last9 = Mihaylova | first9 = V.
| last10 = Von Der Hagen
| doi = 10.1002/humu.22130 | first10 = M.
| last11 = Huebner | first11 = A.
| last12 = Chaouch | first12 = A.
| last13 = Müller | first13 = J. S.
| last14 = Lochmüller | first14 = H.
| title = Congenital myasthenic syndromes: Achievements and limitations of phenotype-guided gene-after-gene sequencing in diagnostic practice: A study of 680 patients
| journal = Human Mutation
| volume = 33
| issue = 10
| pages = 1474–1484
| year = 2012
| pmid = 22678886
| s2cid = 30868022
}} One type of mutation of the epsilon subunit of the AChR introduces an arginine (Arg) into the binding site at the α/ε subunit interface of the receptor. The addition of a cationic Arg into the anionic environment of the AChR binding site greatly reduces the kinetic properties of the receptor. The result of the newly introduced ARG is a 30-fold reduction of agonist affinity, 75-fold reduction of gating efficiency, and an extremely weakened channel opening probability. This type of mutation results in an extremely fatal form of CMS.{{cite journal
| last1 = Shen | first1 = X. -M.
| last2 = Brengman | first2 = J. M.
| last3 = Edvardson | first3 = S.
| last4 = Sine | first4 = S. M.
| last5 = Engel | first5 = A. G.
| title = Highly fatal fast-channel syndrome caused by AChR subunit mutation at the agonist binding site
| doi = 10.1212/WNL.0b013e31825b5bda
| journal = Neurology
| volume = 79
| issue = 5
| pages = 449–454
| year = 2012
| pmid = 22592360
| pmc =3405251
}}
See also
References
{{reflist}}
Further reading
{{refbegin | 2}}
- {{cite journal | vauthors=Hantaï D, Richard P, Koenig J, Eymard B |title=Congenital myasthenic syndromes |journal=Curr. Opin. Neurol. |volume=17 |issue= 5 |pages= 539–51 |year= 2005 |pmid= 15367858 |doi=10.1097/00019052-200410000-00004 |s2cid=45357882 }}
- {{cite journal | vauthors=Yu XM, Hall ZW |title=Extracellular domains mediating epsilon subunit interactions of muscle acetylcholine receptor |journal=Nature |volume=352 |issue= 6330 |pages= 64–7 |year= 1991 |pmid= 1712080 |doi= 10.1038/352064a0 |bibcode=1991Natur.352...64Y |s2cid=4245374 }}
- {{cite journal | author=Ohno K |title=Congenital myasthenic syndrome caused by prolonged acetylcholine receptor channel openings due to a mutation in the M2 domain of the epsilon subunit |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=92 |issue= 3 |pages= 758–62 |year= 1995 |pmid= 7531341 |doi=10.1073/pnas.92.3.758 | pmc=42699 | author2=Hutchinson DO | author3=Milone M | display-authors=3 | last4=Brengman | first4=JM | last5=Bouzat | first5=C | last6=Sine | first6=SM | last7=Engel | first7=AG |doi-access=free }}
- {{cite journal | vauthors=Gomez CM, Gammack JT |title=A leucine-to-phenylalanine substitution in the acetylcholine receptor ion channel in a family with the slow-channel syndrome |journal=Neurology |volume=45 |issue= 5 |pages= 982–5 |year= 1995 |pmid= 7538206 |doi= 10.1212/wnl.45.5.982|s2cid=35877992 }}
- {{cite journal | author=Lobos EA |title=Five subunit genes of the human muscle nicotinic acetylcholine receptor are mapped to two linkage groups on chromosomes 2 and 17 |journal=Genomics |volume=17 |issue= 3 |pages= 642–50 |year= 1993 |pmid= 7902325 |doi= 10.1006/geno.1993.1384 }}
- {{cite journal | author=Brenner HR |title=Nerve-dependent induction of AChR epsilon-subunit gene expression in muscle is independent of state of differentiation |journal=Dev. Biol. |volume=165 |issue= 2 |pages= 527–36 |year= 1994 |pmid= 7958418 |doi=10.1006/dbio.1994.1272 | author2=Rotzler S | author3=Kues WA | display-authors=3 | last4=Witzemann | first4=V | last5=Sakmann | first5=B }}
- {{cite journal | author=Uchitel O |title=Congenital myasthenic syndromes: II. Syndrome attributed to abnormal interaction of acetylcholine with its receptor |journal=Muscle Nerve |volume=16 |issue= 12 |pages= 1293–301 |year= 1993 |pmid= 8232384 |doi= 10.1002/mus.880161205 | author2=Engel AG | author3=Walls TJ | display-authors=3 | last4=Nagel | first4=Alexandre | last5=Atassi | first5=M. Zouhair | last6=Bril | first6=Vera |s2cid=26474245 }}
- {{cite journal | author=Ohno K |title=Congenital myasthenic syndrome caused by decreased agonist binding affinity due to a mutation in the acetylcholine receptor epsilon subunit |journal=Neuron |volume=17 |issue= 1 |pages= 157–70 |year= 1996 |pmid= 8755487 |doi=10.1016/S0896-6273(00)80289-5 | author2=Wang HL | author3=Milone M | display-authors=3 | last4=Bren | first4=Nina | last5=Brengman | first5=Joan M | last6=Nakano | first6=Satoshi | last7=Quiram | first7=Polly | last8=Pruitt | first8=Jerry N | last9=Sine | first9=Steven M |s2cid=17773515 | doi-access=free }}
- {{cite journal | author=Engel AG |title=New mutations in acetylcholine receptor subunit genes reveal heterogeneity in the slow-channel congenital myasthenic syndrome |journal=Hum. Mol. Genet. |volume=5 |issue= 9 |pages= 1217–27 |year= 1997 |pmid= 8872460 |doi=10.1093/hmg/5.9.1217 | author2=Ohno K | author3=Milone M | display-authors=3 | last4=Wang | first4=HL | last5=Nakano | first5=S | last6=Bouzat | first6=C | last7=Pruitt Jn | first7=2nd | last8=Hutchinson | first8=DO | last9=Brengman | first9=JM | doi-access=free }}
- {{cite journal | author=Engel AG |title=End-plate acetylcholine receptor deficiency due to nonsense mutations in the epsilon subunit |journal=Ann. Neurol. |volume=40 |issue= 5 |pages= 810–7 |year= 1997 |pmid= 8957026 |doi= 10.1002/ana.410400521 | author2=Ohno K | author3=Bouzat C | display-authors=3 | last4=Sine | first4=Steven M. | last5=Griggs | first5=Robert C. |s2cid=83884178 |doi-access=free }}
- {{cite journal | author=Ohno K |title=Congenital myasthenic syndromes due to heteroallelic nonsense/missense mutations in the acetylcholine receptor epsilon subunit gene: identification and functional characterization of six new mutations |journal=Hum. Mol. Genet. |volume=6 |issue= 5 |pages= 753–66 |year= 1997 |pmid= 9158150 |doi=10.1093/hmg/6.5.753 | author2=Quiram PA | author3=Milone M | display-authors=3 | last4=Wang | first4=HL | last5=Harper | first5=MC | last6=Pruitt Jn | first6=2nd | last7=Brengman | first7=JM | last8=Pao | first8=L | last9=Fischbeck | first9=KH | doi-access=free }}
- {{cite journal | author=Nichols P |title=Mutation of the acetylcholine receptor epsilon-subunit promoter in congenital myasthenic syndrome |journal=Ann. Neurol. |volume=45 |issue= 4 |pages= 439–43 |year= 1999 |pmid= 10211467 |doi=10.1002/1531-8249(199904)45:4<439::AID-ANA4>3.0.CO;2-W | author2=Croxen R | author3=Vincent A | display-authors=3 | last4=Rutter | first4=Richard | last5=Hutchinson | first5=Michael | last6=Newsom-Davis | first6=John | last7=Beeson | first7=David |s2cid=83632162 }}
- {{cite journal | author=Croxen R |title=Novel functional epsilon-subunit polypeptide generated by a single nucleotide deletion in acetylcholine receptor deficiency congenital myasthenic syndrome |journal=Ann. Neurol. |volume=46 |issue= 4 |pages= 639–47 |year= 1999 |pmid= 10514102 |doi=10.1002/1531-8249(199910)46:4<639::AID-ANA13>3.0.CO;2-1 | author2=Newland C | author3=Betty M | display-authors=3 | last4=Vincent | first4=Angela | last5=Newsom-Davis | first5=John | last6=Beeson | first6=David |s2cid=85150509 }}
- {{cite journal | author=Abicht A |title=A common mutation (epsilon1267delG) in congenital myasthenic patients of Gypsy ethnic origin |journal=Neurology |volume=53 |issue= 7 |pages= 1564–9 |year= 1999 |pmid= 10534268 |doi= 10.1212/wnl.53.7.1564| author2=Stucka R | author3=Karcagi V | display-authors=3 | last4=Herczegfalvi | first4=A | last5=Horváth | first5=R | last6=Mortier | first6=W | last7=Schara | first7=U | last8=Ramaekers | first8=V | last9=Jost | first9=W }}
- {{cite journal | author=Kindler CH |title=Additive inhibition of nicotinic acetylcholine receptors by corticosteroids and the neuromuscular blocking drug vecuronium |journal=Anesthesiology |volume=92 |issue= 3 |pages= 821–32 |year= 2000 |pmid= 10719961 |doi=10.1097/00000542-200003000-00026 | author2=Verotta D | author3=Gray AT | display-authors=3 | last4=Gropper | first4=Michael A. | last5=Yost | first5=C. Spencer |s2cid=27038179 |doi-access=free}}
- {{cite journal | author=Wang HL |title=Fundamental gating mechanism of nicotinic receptor channel revealed by mutation causing a congenital myasthenic syndrome |journal=J. Gen. Physiol. |volume=116 |issue= 3 |pages= 449–62 |year= 2000 |pmid= 10962020 |doi=10.1085/jgp.116.3.449 | pmc=2233692 | author2=Ohno K | author3=Milone M | display-authors=3 | last4=Brengman | first4=JM | last5=Evoli | first5=A | last6=Batocchi | first6=AP | last7=Middleton | first7=LT | last8=Christodoulou | first8=K | last9=Engel | first9=AG }}
- {{cite journal | vauthors=Sieb JP, Kraner S, Rauch M, Steinlein OK |title=Immature end-plates and utrophin deficiency in congenital myasthenic syndrome caused by epsilon-AChR subunit truncating mutations |journal=Hum. Genet. |volume=107 |issue= 2 |pages= 160–4 |year= 2000 |pmid= 11030414 |doi=10.1007/s004390000359 |s2cid=22171041 }}
- {{cite journal | author=Dan I |title=Overlapping of MINK and CHRNE gene loci in the course of mammalian evolution |journal=Nucleic Acids Res. |volume=30 |issue= 13 |pages= 2906–10 |year= 2002 |pmid= 12087176 |doi=10.1093/nar/gkf407 | pmc=117062 | author2=Watanabe NM | author3=Kajikawa E | display-authors=3 | last4=Ishida | first4=T | last5=Pandey | first5=A | last6=Kusumi | first6=A }}
{{refend}}
External links
- {{MeshName|CHRNE+protein,+human}}
- {{UCSC gene info|CHRNE}}
{{NLM content}}
{{Ligand-gated ion channels}}