Translation initiation factor eIF-2B subunit epsilon (EIF2B5)

The protein contains 721 amino acids for an estimated molecular weight of 80380 Da.

 

Catalyzes the exchange of eukaryotic initiation factor 2-bound GDP for GTP. (updated: March 4, 2015)

Protein identification was indicated in the following studies:

  1. Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
  2. 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.
  3. 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.
  4. Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
  5. 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.

PublicationIdentification 1Uniprot mapping 2Not mapped /
Obsolete
TrEMBLSwiss-Prot
Goodman (2013)2289 (gene list)227853205992269
Lange (2014)123412347281224
Hegedus (2015)2638262202352387
Wilson (2016)165815281702911068
d'Alessandro (2017)18261817201815
Bryk (2017)20902060101081942
Chu (2018)18531804553621387

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.

No sequence conservation computed yet.

Interpro domains
Total structural coverage: 25%
Model score: 0

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VariantDescription
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
dbSNP:rs2971409
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
VWM
dbSNP:rs843358
VWM
VWM

The reference OMIM entry for this protein is 603896

Leukoencephalopathy with vanishing white matter; vwm
Childhood ataxia with central nervous system hypomyelinization; cach
Vanishing white matter leukodystrophy
Cree leukoencephalopathy; cle vanishing white matter leukodystrophy with ovarian fai

A number sign (#) is used with this entry because leukoencephalopathy with vanishing white matter (VWM) can be caused by homozygous or compound heterozygous mutation in any of the 5 genes encoding subunits of the translation initiation factor EIF2B: EIF2B1 (606686) on chromosome 12q24, EIF2B2 (606454) on chromosome 14q24, EIF2B3 (606273) on chromosome 1p34, EIF2B4 (606687) on chromosome 2p23, or EIF2B5 (603945) on chromosome 3q27.

DESCRIPTION

Vanishing white matter leukodystrophy is an autosomal recessive neurologic disorder characterized by variable neurologic features, including progressive cerebellar ataxia, spasticity, and cognitive impairment associated with white matter lesions on brain imaging. The age at onset can range from early infancy to adulthood. Rapid neurologic deterioration can occur following minor head trauma. Female mutation carriers may develop ovarian failure, manifest as primary amenorrhea or as secondary amenorrhea lasting more than 6 months, associated with elevated gonadotropin levels at age less than 40 years (summary by Van der Knaap et al., 1998 and Schiffmann et al., 1997).

CLINICAL FEATURES

Van der Knaap et al. (1997) identified 9 children with a 'new' leukoencephalopathy with vanishing white matter. The 9 patients included 3 affected sib pairs; the age range was 3 to 19 years. The onset of the disease was in childhood and the course was chronic, progressive, and episodic. Episodes of deterioration followed infections and minor head traumas, and these could result in unexplained coma. In 8 patients with advanced disease, magnetic resonance imaging (MRI) revealed a diffuse cerebral hemispheric leukoencephalopathy in which increasing areas of the abnormal white matter had a signal intensity close to that of CSF on all pulse sequences. In 1 patient in the early stages of disease, initial MRI showed diffusely abnormal cerebral white matter which only reached the signal characteristics of CSF at a later stage. In the patients in whom the disease was advanced, magnetic resonance spectroscopy (MRS) of the white matter showed an almost complete disappearance of all normal signals and the presence of glucose and lactate compatible with the presence of mainly CSF and little brain tissue. Autopsy in 1 patient confirmed the presence of extensive cystic degeneration of the cerebral white matter with reactive change and a preserved cortex. The disease has an autosomal recessive mode of inheritance. One of the 9 patients who was not part of an affected sib pair had consanguineous parents. Van der Knaap et al. (1998) reported on phenotypic variation in leukoencephalopathy with vanishing white matter in 5 additional patients who met the diagnostic criteria for the disorder except for the age at onset. Four of the patients had onset in late childhood or adolescence, and one was presymptomatic in his early twenties. The course of the disease tended to be milder than in the patients with early childhood onset. Van der Knaap et al. (1998) concluded that later onset does occur in the disease of vanishing white matter and that both MRS and histopathology are compatible with a primary axonopathy rather than primary demyelination. Extensive metabolic investigation in these 5 patients and the 9 previously reported patients failed to determine an underlying cause. Schiffmann et al. (1994) described 4 unrelated girls with progressive ataxic diplegia who had normal development until the ages of 1.5 to 5 years. A ... More on the omim web site

Subscribe to this protein entry history

May 13, 2019: Protein entry updated
Automatic update: model status changed

Nov. 17, 2018: Protein entry updated
Automatic update: model status changed

Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated

Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated

Oct. 27, 2017: Protein entry updated
Automatic update: model status changed

March 16, 2016: Protein entry updated
Automatic update: OMIM entry 603896 was added.

Jan. 25, 2016: Protein entry updated
Automatic update: model status changed