P06624 · MIP_BOVIN
- ProteinLens fiber major intrinsic protein
- GeneMIP
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids263 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Aquaporins form homotetrameric transmembrane channels, with each monomer independently mediating water transport across the plasma membrane along its osmotic gradient (PubMed:23893133, PubMed:30790544).
Specifically expressed in lens fiber cells, this aquaporin is crucial for maintaining lens water homeostasis and transparency. Beyond water permeability, it also acts as a cell-to-cell adhesion molecule, forming thin junctions between lens fiber cells that are essential for maintaining the ordered structure and transparency of the lens (By similarity).
Specifically expressed in lens fiber cells, this aquaporin is crucial for maintaining lens water homeostasis and transparency. Beyond water permeability, it also acts as a cell-to-cell adhesion molecule, forming thin junctions between lens fiber cells that are essential for maintaining the ordered structure and transparency of the lens (By similarity).
Catalytic activity
- H2O(in) = H2O(out)
Activity regulation
The water channel activity is inhibited by calcium through calmodulin/CALM.
Features
Showing features for site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Site | 149 | Important for water channel gating | ||||
Sequence: Y | ||||||
Site | 246 | Interaction with BFSP1 | ||||
Sequence: N | ||||||
Site | 250 | interaction with BFSP1 | ||||
Sequence: E |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | apical plasma membrane | |
Cellular Component | endoplasmic reticulum | |
Cellular Component | gap junction | |
Cellular Component | plasma membrane | |
Molecular Function | calmodulin binding | |
Molecular Function | structural constituent of eye lens | |
Molecular Function | water channel activity | |
Biological Process | gap junction-mediated intercellular transport | |
Biological Process | lens development in camera-type eye | |
Biological Process | positive regulation of cell adhesion | |
Biological Process | protein homotetramerization | |
Biological Process | visual perception | |
Biological Process | water transport |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameLens fiber major intrinsic protein
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Laurasiatheria > Artiodactyla > Ruminantia > Pecora > Bovidae > Bovinae > Bos
Accessions
- Primary accessionP06624
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Cell membrane ; Multi-pass membrane protein
Note: Localizes to thin cell-cell junctions in lens fiber cells.
Features
Showing features for topological domain, transmembrane, intramembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Topological domain | 1-9 | Cytoplasmic | ||||
Sequence: MWELRSASF | ||||||
Transmembrane | 10-29 | Helical; Name=1 | ||||
Sequence: WRAICAEFFASLFYVFFGLG | ||||||
Topological domain | 30-41 | Extracellular | ||||
Sequence: ASLRWAPGPLHV | ||||||
Transmembrane | 42-59 | Helical; Name=2 | ||||
Sequence: LQVALAFGLALATLVQAV | ||||||
Topological domain | 60-61 | Cytoplasmic | ||||
Sequence: GH | ||||||
Intramembrane | 62-77 | Discontinuously helical | ||||
Sequence: ISGAHVNPAVTFAFLV | ||||||
Topological domain | 78-82 | Cytoplasmic | ||||
Sequence: GSQMS | ||||||
Transmembrane | 83-106 | Helical; Name=3 | ||||
Sequence: LLRAICYMVAQLLGAVAGAAVLYS | ||||||
Topological domain | 107-127 | Extracellular | ||||
Sequence: VTPPAVRGNLALNTLHPGVSV | ||||||
Transmembrane | 128-148 | Helical; Name=4 | ||||
Sequence: GQATIVEIFLTLQFVLCIFAT | ||||||
Topological domain | 149-156 | Cytoplasmic | ||||
Sequence: YDERRNGR | ||||||
Transmembrane | 157-175 | Helical; Name=5 | ||||
Sequence: LGSVALAVGFSLTLGHLFG | ||||||
Topological domain | 176-178 | Extracellular | ||||
Sequence: MYY | ||||||
Intramembrane | 179-193 | Discontinuously helical | ||||
Sequence: TGAGMNPARSFAPAI | ||||||
Topological domain | 194-200 | Extracellular | ||||
Sequence: LTRNFTN | ||||||
Transmembrane | 201-222 | Helical; Name=6 | ||||
Sequence: HWVYWVGPVIGAGLGSLLYDFL | ||||||
Topological domain | 223-263 | Cytoplasmic | ||||
Sequence: LFPRLKSVSERLSILKGSRPSESNGQPEVTGEPVELKTQAL |
Keywords
- Cellular component
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 149 | Increases constitutive water permeability. Abolishes regulation by cytoplasmic calcium levels. | ||||
Sequence: Y → G | ||||||
Mutagenesis | 149 | Strongly decreases water permeability. Abolishes regulation by cytoplasmic calcium levels. | ||||
Sequence: Y → L | ||||||
Mutagenesis | 149 | Slightly decreases water permeability, but has a minor effect on the regulation by cytoplasmic calcium levels. | ||||
Sequence: Y → S | ||||||
Mutagenesis | 227 | Strongly reduced CALM binding. | ||||
Sequence: L → A | ||||||
Mutagenesis | 230 | Strongly reduced CALM binding. | ||||
Sequence: V → A |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 89 variants from UniProt as well as other sources including ClinVar and dbSNP.
PTM/Processing
Features
Showing features for chain, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000063910 | 1-263 | Lens fiber major intrinsic protein | |||
Sequence: MWELRSASFWRAICAEFFASLFYVFFGLGASLRWAPGPLHVLQVALAFGLALATLVQAVGHISGAHVNPAVTFAFLVGSQMSLLRAICYMVAQLLGAVAGAAVLYSVTPPAVRGNLALNTLHPGVSVGQATIVEIFLTLQFVLCIFATYDERRNGRLGSVALAVGFSLTLGHLFGMYYTGAGMNPARSFAPAILTRNFTNHWVYWVGPVIGAGLGSLLYDFLLFPRLKSVSERLSILKGSRPSESNGQPEVTGEPVELKTQAL | ||||||
Modified residue | 235 | Phosphoserine | ||||
Sequence: S | ||||||
Modified residue | 243 | Phosphoserine; by PKA | ||||
Sequence: S | ||||||
Modified residue | 245 | Phosphoserine | ||||
Sequence: S | ||||||
Modified residue | 246 | Deamidated asparagine | ||||
Sequence: N |
Post-translational modification
Fatty acylated at Met-1 and Lys-238. The acyl modifications, in decreasing order of ion abundance, are: oleoyl (C18:1) > palmitoyl (C16:0) > stearoyl (C18:0) > eicosenoyl (C20:1) > dihomo-gamma-linolenoyl (C20:3) > palmitoleoyl (C16:1) > eicosadienoyl (C20:2).
Subject to partial proteolytic cleavage in the eye lens core. Partial proteolysis promotes interactions between tetramers from adjoining membranes.
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Tissue specificity
Major component of lens fiber junctions.
Developmental stage
Higher expression in pre-natal (1-5 months gestation) than in postnatal (4-6 months) calf lens.
Gene expression databases
Interaction
Subunit
Homotetramer; each monomer provides an independent water pore (PubMed:15377788, PubMed:16309700).
Two homotetramers on opposing membranes can dimerize, forming a cell-cell junction (PubMed:15377788, PubMed:16309700).
Interacts with CALM; the calcium-calmodulin/CALM complex interacts with the cytoplasmic domains of two aquaporins, leading to channel closure (PubMed:23893133).
Interacts with BFSP1 (via C-terminus); prevents calcium-dependent inhibition of the water channel activity (PubMed:28259670, PubMed:30790544).
Two homotetramers on opposing membranes can dimerize, forming a cell-cell junction (PubMed:15377788, PubMed:16309700).
Interacts with CALM; the calcium-calmodulin/CALM complex interacts with the cytoplasmic domains of two aquaporins, leading to channel closure (PubMed:23893133).
Interacts with BFSP1 (via C-terminus); prevents calcium-dependent inhibition of the water channel activity (PubMed:28259670, PubMed:30790544).
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for motif, region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Motif | 68-70 | NPA 1 | ||||
Sequence: NPA | ||||||
Motif | 184-186 | NPA 2 | ||||
Sequence: NPA | ||||||
Region | 227-237 | Interaction with CALM | ||||
Sequence: LKSVSERLSIL | ||||||
Region | 239-263 | Disordered | ||||
Sequence: GSRPSESNGQPEVTGEPVELKTQAL |
Domain
Aquaporins contain two tandem repeats each containing three membrane-spanning domains and a pore-forming loop with the signature motif Asn-Pro-Ala (NPA).
Sequence similarities
Belongs to the MIP/aquaporin (TC 1.A.8) family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length263
- Mass (Da)28,223
- Last updated1988-01-01 v1
- ChecksumE08C2C4F33398D4E
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 14 | in Ref. 2; AA sequence | ||||
Sequence: C → L | ||||||
Sequence conflict | 29-33 | in Ref. 2; AA sequence | ||||
Sequence: GASLR → RAFLL |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
K02818 EMBL· GenBank· DDBJ | AAA30622.1 EMBL· GenBank· DDBJ | mRNA |