Unconventional myosin-Ic (MYO1C)
The protein contains 1063 amino acids for an estimated molecular weight of 121682 Da.
Myosins are actin-based motor molecules with ATPase activity. Unconventional myosins serve in intracellular movements. Their highly divergent tails are presumed to bind to membranous compartments, which would be moved relative to actin filaments. Involved in glucose transporter recycling in response to insulin by regulating movement of intracellular GLUT4-containing vesicles to the plasma membrane. Component of the hair cell's (the sensory cells of the inner ear) adaptation-motor complex. Acts as a mediator of adaptation of mechanoelectrical transduction in stereocilia of vestibular hair cells. Binds phosphoinositides and links the actin cytoskeleton to cellular membranes.Isoform 3 is involved in regulation of transcription. Associated with transcriptional active ribosomal genes. Appears to cooperate with the WICH chromatin-remodeling complex to facilitate transcription. Necessary for the formation of the first phosphodiester bond during transcription initiation (By similarity). (updated: April 1, 2015)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
This protein is annotated as membranous in Gene Ontology, is annotated as membranous in UniProt.
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| Variant | Description |
|---|---|
| dbSNP:rs8081370 | |
| dbSNP:rs9905106 |
Biological Process
Actin filament organization
Cellular response to interferon-gamma
Fc-gamma receptor signaling pathway involved in phagocytosis
Innate immune response
Membrane organization
Microtubule-based movement
MRNA transport
Positive regulation of actin filament polymerization
Positive regulation of cell migration
Positive regulation of cell migration by vascular endothelial growth factor signaling pathway
Positive regulation of cellular response to insulin stimulus
Positive regulation of gene expression, epigenetic
Positive regulation of protein targeting to membrane
Positive regulation of vascular endothelial growth factor signaling pathway
Protein targeting
Protein targeting to membrane
Regulation of bicellular tight junction assembly
Vesicle transport along actin filament
Cellular Component
Actin cytoskeleton
Basal plasma membrane
Brush border
Cytoplasm
Cytoplasmic vesicle membrane
Cytoplasmic, membrane-bounded vesicle
Cytosol
Extracellular exosome
Filamentous actin
Lateral plasma membrane
Membrane
Membrane raft
Microvillus
Mitochondrion
Myosin I complex
Nuclear body
Nuclear pore
Nucleolus
Nucleoplasm
Obsolete cell
Phagocytic vesicle
Plasma membrane
Ruffle
Ruffle membrane
Stereocilium membrane
Unconventional myosin complex
Vesicle
The reference OMIM entry for this protein is 606538
Myosin ic; myo1c
Myosin 2, rat, homolog of; myr2
Nuclear myosin i; nmi
Myosins are molecular motors that, upon interaction with actin filaments, utilize energy from ATP hydrolysis to generate mechanical force. For further background information on myosins, see MYO1A (601478).
CLONING
By screening a kidney cDNA library with a mouse Myo1c probe, Crozet et al. (1997) obtained a human cDNA encoding MYO1C. The deduced 1,028-amino acid protein, which is 96% identical to the mouse protein, contains ATP- and actin-binding sequences in the motor (or head) domain, followed by three 23-residue IQ motifs and a tail domain rich in basic residues that is expected to interact with negatively charged membrane phospholipids. Northern blot analysis revealed ubiquitous expression of Myo1c in adult mouse tissues.GENE FUNCTION
MYO1C, also known as myosin I-beta and MYR2, was thought to mediate the slow component of adaptation by hair cells, the sensory cells of the inner ear. To test this hypothesis, Holt et al. (2002) mutated tyr61 of MYO1C to gly, conferring susceptibility to inhibition by N6-modified ADP analogs. They expressed the mutant MYO1C in utricular hair cells of transgenic mice, delivered an ADP analog through a whole-cell recording pipette, and found that the analog rapidly blocked adaptation to positive and negative deflections in transgenic cells but not in wildtype cells. The speed and specificity of inhibition suggested that MYO1C participates in adaptation in hair cells. Bose et al. (2002) reported that the unconventional myosin MYO1C is present in GLUT4 (138190)-containing vesicles purified from 3T3-L1 adipocytes. MYO1C is highly expressed in primary and cultured adipocytes. Insulin (176730) enhances the localization of MYO1C with GLUT4 in cortical tubulovesicular structures associated with actin filaments, and this colocalization is insensitive to wortmannin. Insulin-stimulated translocation of GLUT4 to the adipocyte plasma membrane is augmented by the expression of wildtype MYO1C and inhibited by a dominant-negative cargo domain of MYO1C. A decrease in the expression of endogenous MYO1C mediated by small interfering RNAs inhibited insulin-stimulated uptake of 2-deoxyglucose. Thus, Bose et al. (2002) concluded that MYO1C functions in a phosphatidylinositol-3-hydroxykinase (PI3K; see 601232)-independent insulin signaling pathway that controls the movement of intracellular GLUT4-containing vesicles to the plasma membrane.MAPPING
Using PCR and radiation hybrid analysis, Crozet et al. (1997) mapped the MYO1C gene to 17p13.HISTORY
A report by Nunez et al. (2008) indicating that 3-dimensional motor-dependent interchromosomal interactions involving MYO1C are required to achieve enhanced transcription of specific estrogen-receptor target genes was retracted. ... More on the omim web site
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 606538 was added.