Gi alpha subunit

guanine nucleotide binding protein (G protein), alpha inhibiting activity polypeptide 2
guanine nucleotide binding protein (G protein), alpha inhibiting activity polypeptide 2
Identifiers
Symbol	GNAI2
Alt. symbols	GNAI2B
NCBI gene	2771
HGNC	4385
OMIM	139360
RefSeq	NM_002070
UniProt	P04899
Other data
Locus	Chr. 3 p21
Structures
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Structures	Swiss-model
Domains	InterPro

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Structures	Swiss-model
Domains	InterPro

guanine nucleotide binding protein (G protein), alpha inhibiting activity polypeptide 1
guanine nucleotide binding protein (G protein), alpha inhibiting activity polypeptide 1
Identifiers
Symbol	GNAI1
NCBI gene	2770
HGNC	4384
OMIM	139310
RefSeq	NM_002069
UniProt	P63096
Other data
Locus	Chr. 7 q21-q22
Structures
Search for
Structures	Swiss-model
Domains	InterPro

guanine nucleotide binding protein (G protein), alpha inhibiting activity polypeptide 3

Identifiers

Symbol

Other data

Chr. 1 p13

Search for
Structures	Swiss-model
Domains	InterPro

G_i alpha subunit (or G_i/G₀ or Gi protein) is a heterotrimeric G protein subunit which inhibits the production of cAMP from ATP.^[1]

Receptors

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

Function

G_i inhibits adenylate cyclase activity, decreasing the production of cAMP from ATP, which, in turn, results in decreased activity of cAMP-dependent protein kinase. Thus, the ultimate effect of G_i is thus the opposite of cAMP-dependent protein kinase, which can be found at function of cAMP-dependent protein kinase.

Types

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

Gia1

Gia1 or G_i1 is encoded by the gene GNAI1.

Gia2

Gia2 or G_i2 is encoded by the gene GNAI2.

Gia3

Gia3 or G_i3 is encoded by the gene GNAI3.

References

^ Birnbaumer L (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. {{cite journal}}: Unknown parameter |month= ignored (help)

External links

Gi+alpha+Subunit at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

This biochemistry article is a stub. You can help Wikipedia by expanding it.

[pmid17258171-1] Birnbaumer L (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. {{cite journal}}: Unknown parameter |month= ignored (help)

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