Small membrane A-kinase anchor protein (C2orf88)
The protein contains 95 amino acids for an estimated molecular weight of 10970 Da.
Binds to type I regulatory subunits of protein kinase A (PKA-RI) and may anchor/target them to the plasma membrane. (updated: Feb. 4, 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.
- 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.
- Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
- 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.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
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:rs6753459 |
No binding partner found
Biological Process
The reference OMIM entry for this protein is 615117
Chromosome 2 open reading frame 88; c2orf88
Small membrane protein kinase a-anchoring protein; smakap
DESCRIPTION
Protein kinase A (PKA; see 601639)-anchoring proteins (AKAPs) provide spatiotemporal specificity for the omnipotent cAMP-dependent PKA via high-affinity interactions with PKA regulatory subunits. C2ORF88, or SMAKAP, is an AKAP that specifically localizes type I PKA regulatory subunits (e.g., PRKAR1A; 188830) to the plasma membrane (Burgers et al., 2012).CLONING
Using a cAMP affinity-based chemical proteomics approach in human heart and platelets, Burgers et al. (2012) identified C2ORF88, which they termed SMAKAP. The predicted 95-amino acid protein contains a 14-residue PKA-anchoring motif near its C terminus. Database analysis identified SMAKAP orthologs in mammals, birds, and fish. RT-PCR analysis of mouse tissues detected ubiquitous Smakap expression, with lowest levels in spleen and liver. Transient transfection and fluorescence and electron microscopy experiments demonstrated localization of human SMAKAP at the plasma membrane and particularly with filopodia and at cell-cell junctions.GENE FUNCTION
Using in vitro binding assays and in vivo localization and competition experiments, Burgers et al. (2012) showed that human SMAKAP selectively localized type I PKA regulatory subunits to the plasma membrane. Mutation analysis suggested that SMAKAP localizes to the plasma membrane via myristoylation/palmitoylation of its N terminus.MAPPING
Gross (2013) mapped the C2ORF88 gene to chromosome 2q32.2 based on an alignment of the C2ORF88 sequence (GenBank GENBANK BC005083) with the genomic sequence (GRCh37). ... 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 615117 was added.