Gi alpha subunit: Difference between revisions

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{{protein
{{DISPLAYTITLE:G<sub>i</sub> alpha subunit}}
| Name = [[GNAI1|guanine nucleotide binding protein (G protein), alpha inhibiting activity polypeptide 1]]
{{infobox protein
| Name = [[GNAI1|G protein subunit alpha i1]]
| caption =  
| caption =  
| image =  
| image =  
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| RefSeq = NM_002069
| RefSeq = NM_002069
| UniProt = P63096
| UniProt = P63096
| PDB =  
| PDB = 3UMR
| ECnumber =  
| ECnumber =  
| Chromosome = 7
| Chromosome = 7
Line 18: Line 19:
| LocusSupplementaryData = -q22
| LocusSupplementaryData = -q22
}}
}}
{{protein
{{infobox protein
| Name = [[GNAI2|guanine nucleotide binding protein (G protein), alpha inhibiting activity polypeptide 2]]
| Name = [[GNAI2|G protein subunit alpha i2]]
| caption =  
| caption =  
| image =  
| image =  
Line 25: Line 26:
| HGNCid = 4385
| HGNCid = 4385
| Symbol = [[GNAI2]]
| Symbol = [[GNAI2]]
| AltSymbols = GNAI2B
| AltSymbols =  
| EntrezGene = 2771
| EntrezGene = 2771
| OMIM = 139360
| OMIM = 139360
Line 37: Line 38:
| LocusSupplementaryData =  
| LocusSupplementaryData =  
}}
}}
{{protein
{{infobox protein
| Name = guanine nucleotide binding protein (G protein), alpha inhibiting activity polypeptide 3
| Name = [[GNAI3|G protein subunit alpha i3]]
| caption =  
| caption =  
| image =  
| image =  
| width =  
| width =  
| HGNCid = 4387
| HGNCid = 4387
| Symbol = GNAI3
| Symbol = [[GNAI3]]
| AltSymbols =  
| AltSymbols =  
| EntrezGene = 2773
| EntrezGene = 2773
Line 49: Line 50:
| RefSeq = NM_006496
| RefSeq = NM_006496
| UniProt = P08754
| UniProt = P08754
| PDB =  
| PDB = 2ODE
| ECnumber =  
| ECnumber =  
| Chromosome = 1
| Chromosome = 1
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| LocusSupplementaryData =  
| LocusSupplementaryData =  
}}
}}
{{infobox protein
| Name = [[GNAO1|G protein subunit alpha o1]]
| caption =
| image =
| width =
| HGNCid = 4389
| Symbol = [[GNAO1]]
| AltSymbols =
| EntrezGene = 2775
| OMIM = 139311
| RefSeq = NM_020988
| UniProt = P09471
| PDB =
| ECnumber =
| Chromosome = 16
| Arm = q
| Band = 13
| LocusSupplementaryData =
}}
'''G<sub>i</sub> alpha subunit''' ('''G<sub>αi</sub>''', or '''G<sub>i</sub>/G<sub>0</sub>''' or '''G<sub>i</sub> protein''') is a [[heterotrimeric G protein]] subunit that inhibits the production of [[Cyclic adenosine monophosphate|cAMP]] from [[Adenosine triphosphate|ATP]].<ref name="pmid17258171">{{cite journal | author = Birnbaumer L | title = Expansion of signal transduction by G proteins. The second 15 years or so: from 3 to 16 alpha subunits plus betagamma dimers | journal = Biochim. Biophys. Acta | volume = 1768 | issue = 4 | pages = 772–93 |date=April 2007 | pmid = 17258171 | pmc = 1993906 | doi = 10.1016/j.bbamem.2006.12.002 | url = | issn = }}</ref> A mnemonic for remembering this subunit is to look at first letter  (G<sub>'''αi'''</sub> = [[Adenylyl cyclase|'''A'''denylyl Cyclase]] '''i'''nhibitor).
== Receptors ==
The following [[G protein-coupled receptors]] couple to the G<sub>i</sub> subunit:


* [[Acetylcholine]] [[Muscarinic acetylcholine receptor M2|M<sub>2</sub>]] & [[Muscarinic acetylcholine receptor M4|M<sub>4</sub>]] receptors
* [[Adenosine]] [[Adenosine receptor A1|A<sub>1</sub>]] & [[Adenosine receptor A3|A<sub>3</sub>]] receptors
* [[Adrenergic]] [[ADRA2A|α<sub>2A</sub>]], [[ADRA2B|α<sub>2B</sub>]], & [[ADRA2C|α<sub>2C</sub>]] receptors
* [[Apelin]] receptors
* [[Calcium-sensing receptor]]
* [[Cannabinoid receptor]]s ([[Cannabinoid receptor type 1|CB1]] and [[Cannabinoid receptor type 2|CB2]])
* [[Chemokine]] [[CXCR4]] receptor
* [[Dopamine]] [[Dopamine D2 receptor|D<sub>2</sub>]], [[Dopamine D3 receptor|D<sub>3</sub>]], [[Dopamine D4 receptor|D<sub>4</sub>]]
* [[GABA-B receptor|GABA<sub>B</sub>]] receptor
* [[Glutamate]] [[MGlu2|mGlu<sub>2</sub>]], [[MGlu3|mGlu<sub>3</sub>]], [[mGluR4|mGlu<sub>4</sub>]], [[mGluR6|mGlu<sub>6</sub>]], [[mGluR7|mGlu<sub>7</sub>]], & [[mGluR8|mGlu<sub>8</sub>]] receptors
* [[Histamine]] [[Histamine H3 receptor|H<sub>3</sub>]] & [[Histamine H4 receptor|H<sub>4</sub>]] receptors
* [[Melatonin]] [[MTNR1A|MT<sub>1</sub>]], [[MTNR1B|MT<sub>2</sub>]], & [[MTNR1C|MT<sub>3</sub>]] receptors
* [[Hydroxycarboxylic acid receptors]]: [[HCA1]], [[HCA2]], & [[HCA3]]
* [[Opioid]] [[Delta Opioid receptor|δ]], [[Kappa Opioid receptor|κ]], [[Mu Opioid receptor|μ]], & [[Nociceptin receptor|nociceptin]] receptors
* [[Prostaglandin]] [[PTGER1|EP<sub>1</sub>]], [[PTGER3|EP<sub>3</sub>]], [[FP receptor|FP]], & [[Thromboxane receptor|TP]] receptors
* [[Serotonin]] [[5-HT1|5-HT<sub>1</sub>]] & [[5-HT5A|5-HT<sub>5</sub>]] receptors
* [[Short chain fatty acid]] receptors: [[FFAR2]] & [[FFAR3]]
* [[Somatostatin]] [[Somatostatin receptor 1|sst1]], [[Somatostatin receptor 2|sst2]], [[Somatostatin receptor 3|sst3]], [[Somatostatin receptor 4|sst4]] & [[Somatostatin receptor 5|sst5]] receptors
* [[Trace amine-associated receptor 8]]


==Overview==
== Function ==
'''G<sub>i</sub> alpha subunit''' (or '''G<sub>i</sub>/G<sub>0</sub>''' or '''Gi protein''') is a [[heterotrimeric G protein]] subunit which inhibits the production of [[Cyclic_adenosine_monophosphate|cAMP]] from [[Adenosine triphosphate|ATP]].


==Receptors==
{{See also|function of cAMP-dependent protein kinase}}
The following [[G-protein coupled receptors]] couple to the G<sub>i</sub> subunit:
*[[5-HT receptor]] type 1
* [[Adenosine receptor A1]] and [[Adenosine receptor A3|A3]]
* [[Prostaglandins]]


==Function==
G<sub>i</sub> mainly inhibits the [[cAMP dependent pathway]] by inhibiting adenylate cyclase activity, decreasing the production of [[Cyclic adenosine monophosphate|cAMP]] from [[Adenosine triphosphate|ATP]], which, in turn, results in decreased activity of [[cAMP-dependent protein kinase]]. Therefore, the ultimate effect of G<sub>i</sub> is the opposite of [[function of cAMP-dependent protein kinase|cAMP-dependent protein kinase]].
''Further reading: [[function of cAMP-dependent protein kinase]]''


G<sub>i</sub> inhibits the production of [[Cyclic_adenosine_monophosphate|cAMP]] from [[Adenosine triphosphate|ATP]], which, in turn, results in decreased activity of [[cAMP-dependent protein kinase]]. Thus, the ultimate effect of G<sub>i</sub> is thus the opposite of cAMP-dependent protein kinase, which can be found at [[function of cAMP-dependent protein kinase]].
It is also attributed a minor role in activation of the [[phospholipase C pathway]].<ref>{{cite journal |vauthors=Obál F, Krueger J | title = The somatotropic axis and sleep. | journal = Rev Neurol (Paris) | volume = 157 | issue = 11 Pt 2 | pages = S12–5 | year = 2001 | pmid = 11924022}}</ref> Growth hormone is required for normal postnatal growth, bone growth, regulatory effects on protein, carbohydrate, and lipid metabolism.<ref name=GeneGlobe>[https://www1.qiagen.com/GeneGlobe/PathwayView.aspx?pathwayID=199 GeneGlobe -> GHRH Signaling]{{dead link|date=October 2017 |bot=InternetArchiveBot |fix-attempted=yes }} Retrieved on May 31, 2009</ref> Although this is mainly a function of the [[Gq alpha subunit|G<sub>q</sub> alpha subunit]].


==Types==
== Types ==
There are several types of G<sub>i</sub>: Gia1, Gia2, Gia3 and Gia4
There are several types of G<sub>i</sub>: Gia1, Gia2, Gia3 and Gia4


===Gia1=== <!--Gia1 redirects here-->
=== Gia1 === <!--Gia1 redirects here-->
Gia1 or G<sub>i1</sub> is encoded by the gene [[GNAI1]].
Gia1 or G<sub>i1</sub> is encoded by the gene [[GNAI1]].


===Gia2=== <!--Gia2 redirects here-->
=== Gia2 === <!--Gia2 redirects here-->
Gia2 or G<sub>i2</sub> is encoded by the gene [[GNAI2]].
Gia2 or G<sub>i2</sub> is encoded by the gene [[GNAI2]].


===Gia3=== <!--Gia3 redirects here-->
=== Gia3 === <!--Gia3 redirects here-->
Gia3 or G<sub>i3</sub> is encoded by the gene {{gene|GNAI3}}.
Gia3 or G<sub>i3</sub> is encoded by the gene [[GNAI3]].


==See also==
== See also ==
* [[Second messenger system]]
* [[Second messenger system]]


==External links==
== References ==
{{Reflist}}
 
== External links ==
* {{MeshName|Gi+alpha+Subunit}}
* {{MeshName|Gi+alpha+Subunit}}


{{biochem-stub}}
{{Intracellular signaling peptides and proteins}}
{{GTPases}}
{{Acid anhydride hydrolases}}
{{Enzymes}}
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[[Category:G proteins|*]]
[[Category:G proteins|*]]
[[Category:Peripheral membrane proteins]]
[[Category:Peripheral membrane proteins]]
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Latest revision as of 09:24, 10 January 2019

G protein subunit alpha i1
Identifiers
SymbolGNAI1
Entrez2770
HUGO4384
OMIM139310
PDB3UMR
RefSeqNM_002069
UniProtP63096
Other data
LocusChr. 7 q21-q22
G protein subunit alpha i2
Identifiers
SymbolGNAI2
Entrez2771
HUGO4385
OMIM139360
RefSeqNM_002070
UniProtP04899
Other data
LocusChr. 3 p21
G protein subunit alpha i3
Identifiers
SymbolGNAI3
Entrez2773
HUGO4387
OMIM139370
PDB2ODE
RefSeqNM_006496
UniProtP08754
Other data
LocusChr. 1 p13
G protein subunit alpha o1
Identifiers
SymbolGNAO1
Entrez2775
HUGO4389
OMIM139311
RefSeqNM_020988
UniProtP09471
Other data
LocusChr. 16 q13

Gi alpha subunit (Gαi, or Gi/G0 or Gi protein) is a heterotrimeric G protein subunit that inhibits the production of cAMP from ATP.[1] A mnemonic for remembering this subunit is to look at first letter (Gαi = Adenylyl Cyclase inhibitor).

Receptors

The following G protein-coupled receptors couple to the Gi subunit:

Function

Gi mainly inhibits the cAMP dependent pathway by inhibiting adenylate cyclase activity, decreasing the production of cAMP from ATP, which, in turn, results in decreased activity of cAMP-dependent protein kinase. Therefore, the ultimate effect of Gi is the opposite of cAMP-dependent protein kinase.

It is also attributed a minor role in activation of the phospholipase C pathway.[2] Growth hormone is required for normal postnatal growth, bone growth, regulatory effects on protein, carbohydrate, and lipid metabolism.[3] Although this is mainly a function of the Gq alpha subunit.

Types

There are several types of Gi: Gia1, Gia2, Gia3 and Gia4

Gia1

Gia1 or Gi1 is encoded by the gene GNAI1.

Gia2

Gia2 or Gi2 is encoded by the gene GNAI2.

Gia3

Gia3 or Gi3 is encoded by the gene GNAI3.

See also

References

  1. Birnbaumer L (April 2007). "Expansion of signal transduction by G proteins. The second 15 years or so: from 3 to 16 alpha subunits plus betagamma dimers". Biochim. Biophys. Acta. 1768 (4): 772–93. doi:10.1016/j.bbamem.2006.12.002. PMC 1993906. PMID 17258171.
  2. Obál F, Krueger J (2001). "The somatotropic axis and sleep". Rev Neurol (Paris). 157 (11 Pt 2): S12–5. PMID 11924022.
  3. GeneGlobe -> GHRH Signaling[permanent dead link] Retrieved on May 31, 2009

External links