Tubulin beta-4B chain (TUBB4B)
The protein contains 445 amino acids for an estimated molecular weight of 49831 Da.
Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain. (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.
- 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.
Biological Process
'de novo' posttranslational protein folding
Cellular protein metabolic process
Ciliary basal body-plasma membrane docking
G2/M transition of mitotic cell cycle
Microtubule cytoskeleton organization
Microtubule-based process
Mitotic cell cycle
Movement of cell or subcellular component
Natural killer cell mediated cytotoxicity
Neutrophil degranulation
Organelle organization
Protein folding
Protein polymerization
Regulation of G2/M transition of mitotic cell cycle
Spindle assembly
Transmembrane transport
The reference OMIM entry for this protein is 602660
Tubulin, beta-4b; tubb4b
Tubulin, beta-2c; tubb2c
Tubulin, beta-2
Tubulin, beta, class ivb
DESCRIPTION
Microtubules are dynamic polymeric structures consisting of heterodimers of alpha-tubulins (see 602529) and beta-tubulins, such as TUBB4B, that are continuously incorporated and released. Microtubules function in mitosis, intracellular transport, neuron morphology, and ciliary and flagellar motility (Leandro-Garcia et al., 2010).CLONING
Lewis et al. (1985) cloned the tubulin beta-2 isoform gene. The beta-2 gene is expressed as a 1.8-kb mRNA, and the sequence encodes a predicted 445-amino acid protein. Lewis and Cowan (1990) stated that the mouse homolog of beta-2, M-beta-3, is expressed abundantly in testis and at lower levels in many other tissues. Using database analysis, Leandro-Garcia et al. (2010) identified 8 major beta-tubulins, including TUBB4B, which they called TUBB2C. Quantitative RT-PCR showed variable TUBB2C expression in all 21 normal human tissues examined, with highest expression in heart and testis, and lowest expression in prostate. TUBB2C was the predominant beta-tubulin isotype in testis, kidney, heart, skeletal muscle, and lung. Abnormal TUBB2C expression was detected in several tumors compared with their normal counterparts.GENE FAMILY
Lewis and Cowan (1990) reviewed the beta-tubulin gene family. In humans, this family consists of 15 to 20 dispersed genes, many of which are processed pseudogenes. The positions of the first 2 introns are identical among members of the human and chicken gene families. Within a vertebrate species, the genes are distinguished by their C-terminal region. The amino acid sequence differences show varying degrees of conservation across species, depending on the isotype.MAPPING
Hartz (2013) mapped the TUBB4B gene to chromosome 9q34.3 based on an alignment of the TUBB4B sequence (GenBank GENBANK BC001911) 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
June 20, 2017: Protein entry updated
Automatic update: comparative model was added.
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 602660 was added.