Inositol triphosphate receptor

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inositol 1,4,5-triphosphate receptor, type 1
Identifiers
Symbol	ITPR1
Entrez	3708
HUGO	6180
OMIM	147265
RefSeq	NM_002222
UniProt	Q14643
Other data
Locus	Chr. 3 p26.1

inositol 1,4,5-triphosphate receptor, type 2
Identifiers
Symbol	ITPR2
Entrez	3709
HUGO	6181
OMIM	600144
RefSeq	NM_002223
UniProt	Q14571
Other data
Locus	Chr. 12 p11.23

inositol 1,4,5-triphosphate receptor, type 3
Identifiers
Symbol	ITPR3
Entrez	3710
HUGO	6182
OMIM	147267
RefSeq	NM_002224
UniProt	Q14573
Other data
Locus	Chr. 6 p21.31

Inositol triphosphate receptor (IP3R) is a membrane glycoprotein complex acting as Ca²⁺ channel activated by inositol triphosphate (IP3). The IP3 receptor was first purified from rat cerebellum^[1].

Contents 1 Distribution 2 Structure 3 See also 4 References 5 External links

[edit] Distribution

It has a broad tissue distribution but is especially abundant in the cerebellum. Most of the IP3R's are found in the cell integrated into the endoplasmic reticulum.

[edit] Structure

The IP3R complex is formed of four 313 kDa subunits. In amphibians, fish and mammals there are 3 paralogs and these can form homo- or hetero-oligomers. IP3R-1 is the most widely expressed of these three and is found in all tissue types and all developmental stages of life. It is additionally the means for further IP3 receptor diversity in that it has as many as four splice sites with as many as 9 different optional exons or exon variants. Combinations of these can be introduced into a given transcript in order to modulate its pharmacological activity.

[edit] See also

• inositol
• inositol phosphate
  • inositol monophosphate
  • inositol triphosphate
  • inositol pentakisphosphate
  • inositol hexaphosphate

[edit] References

1. ^ Inositol trisphosphate receptor Ca2+ release chann...[Physiol Rev. 2007] - PubMed Result

[edit] External links

• MeSH Inositol+Triphosphate+Receptor

v • d • e Cell signaling: lipid signaling Phospholipase - PIP2 - DAG - IP3 - IP3 receptor

v • d • e Membrane transport protein: ion channels Ca2+: Calcium channel Voltage-dependent calcium channel (L-type/Cavα(1.1, 1.2, 1.3, 1.4), N-type, P-type/Cavα(2.1), Q-type, R-type, T-type, α2δ-subunits (1, 2), β-subunits (β1, β2, β3, β4), γ-subunits (γ1, γ2, γ3, γ4) Inositol triphosphate receptor • Ryanodine receptor • Cation channels of sperm • Two-pore channel Na+: Sodium channel Navα (1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.9, 7A) • Navβ (1, 2, 3, 4) • Epithelial sodium channel K+: Potassium channel Voltage-gated (Kvα (1.1, 1.2, 1.3, 1.4, 1.5, 2.1, 3.1, 3.4, 4.1, 4.2, 4.3, 6.1, 7.1, 7.2, 7.3, 7.4, 7.5, 9.3, 10.1, 11.1/hERG) • Kvβ (1, 2), Shaker gene, KCNE1) Calcium-activated (BK channel: α1, β1, β2, β3, β4; SK channel: SK1, SK2, SK3, SK4) Inward-rectifier Kir (1.1, 2.1, 2.2, 2.3, 2.4, GIRK, 3.1, 3.2, 3.3, 3.4, 4.1, 4.2, 5.1, 6.1, 6.2, 7.1) Tandem pore domain K2P (1, 2, 3, 4, 6, 9, 15, 17) Cl-: Chloride channel Cystic fibrosis transmembrane conductance regulator Porin Aquaporin (1, 2, 3, 4, 5, 7, 8, 9) • Voltage-dependent anion channel (1) Cations: TRP TRPA (1) • TRPC (1, 2, 3, 4, 4AP, 5, 6, 7) • TRPM (1, 2, 3, 4, 5, 6, 7, 8) • TRPML (Mucolipin-1) • TRPP (1, 2) • TRPV (1, 2, 3, 4, 5, 6) Other/general Voltage-gated ion channel • Ligand-gated ion channel • Cyclic nucleotide-gated ion channel (α1, α2, α3, β1, β3, H1, H2, H3, H4) • Stretch-activated ion channel