Stoichiometry of the eIF2B complex is maintained by mutual stabilization of subunits.

The eukaryotic translation initiation factor eIF2B is a multi-subunit complex with a crucial role in the regulation of global protein synthesis in the cell. The complex comprises five subunits, termed α through ε in order of increasing size, arranged as a heterodecamer with two copies of each subunit. Regulation of the co-stoichiometric expression of the eIF2B subunits is crucial for the proper function and regulation of the eIF2B complex in cells.

eIF2B: recent structural and functional insights into a key regulator of translation.

The eukaryotic translation initiation factor (eIF) eIF2B is a key regulator of mRNA translation, being the guanine nt exchange factor (GEF) responsible for the recycling of the heterotrimeric G-protein, eIF2, which is required to allow translation initiation to occur. Unusually for a GEF, eIF2B is a multi-subunit protein, comprising five different subunits termed α through ε in order of increasing size. eIF2B is subject to tight regulation in the cell and may also serve additional functions.

Biochemical effects of mutations in the gene encoding the alpha subunit of eukaryotic initiation factor (eIF) 2B associated with Vanishing White Matter disease.

Background: Leukoencephalopathy with Vanishing White Matter (VWM) is an autosomal recessive disorder caused by germline mutations in the genes EIF2B1-5, which encode the 5 subunits of the eukaryotic translation initiation factor eIF2B. To date, analysis of the biochemical effects of mutations in the EIF2B2-5 genes has been carried out, but no study has been performed on mutations in the EIF2B1 gene. This gene encodes eIF2Bα, the smallest subunit in eIF2B which has an important role in both the structure and regulation of the eIF2B complex.

Analysis of the subunit organization of the eIF2B complex reveals new insights into its structure and regulation.

Eukaryotic initiation factor 2B (eIF2B) is the guanine nucleotide exchange factor for eIF2 and a critical regulator of protein synthesis, (e.g., as part of the integrated stress response).

Identification of residues that underpin interactions within the eukaryotic initiation factor (eIF2) 2B complex.

Eukaryotic initiation factor 2B (eIF2B) plays a key role in protein synthesis and in its control. It comprises five different subunits, α-ε, of which eIF2Bε contains the catalytic domain. Formation of the complete complex is crucial for full activity and proper control of eIF2B.

Severity of vanishing white matter disease does not correlate with deficits in eIF2B activity or the integrity of eIF2B complexes.

Autosomal recessive mutations in eukaryotic initiation factor 2B (eIF2B) cause leukoencephalopathy vanishing white matter with a wide clinical spectrum. eIF2B comprises five subunits (α-ε; genes EIF2B1, 2, 3, 4 and 5) and is the guanine nucleotide-exchange factor (GEF) for eIF2. It plays a key role in protein synthesis.

Definition of a minimal region of deletion of chromosome 7 in uterine leiomyomas by tiling-path microarray CGH and mutation analysis of known genes in this region.

Somatic interstitial deletions of chromosome segment 7q22-q31 in uterine leiomyomas are a frequent event, thought to be indicative of a tumor suppressor gene in the region. Previous LOH and CGH studies have refined this region to 7q22.3-q31, although the target gene has not been identified.

Aberrant expression of apoptosis proteins and ultrastructural aberrations in uterine leiomyomas from patients with hereditary leiomyomatosis and renal cell carcinoma.

Objective: To examine differences between sporadic and familial uterine leiomyomata related to expression of apoptosis-related proteins and tumor ultrastructure.

Design: Expression of apoptosis-related proteins was measured by immunohistochemistry. Tumor ultrastructure was evaluated by transmission electron microscopy.

Adult leydig cell tumors of the testis caused by germline fumarate hydratase mutations.

Context: Leydig cell tumors (LCTs) are the most common non-germ-cell neoplasms of the testis. LCTs are often hormonally active and can result in precocious virilization or in adult feminization. We identified an LCT in an affected individual from a kindred with hereditary leiomyomatosis and renal cell cancer (HLRCC) and a germline fumarate hydratase (FH) mutation (N64T).

CDC4 mutations occur in a subset of colorectal cancers but are not predicted to cause loss of function and are not associated with chromosomal instability.

CDC4/FBXW7 is part of a ubiquitin ligase complex which targets molecules such as cyclin E, c-myc, and c-jun for destruction. CDC4 mutations occur in several cancer types and are best described in colorectal tumors. Knockout of CDC4 in vitro in colorectal cancer cells causes changes suggestive of chromosomal instability (CIN).

7q deletion mapping and expression profiling in uterine fibroids.

Uterine fibroids are some of the most common tumours of females, but relatively little is known about their molecular basis. Several studies have suggested that deletions on chromosome 7q could have a role in fibroid formation. We analysed 165 sporadic uterine fibroids to define a small 3.

Dercum's disease.

Dercum's disease (adiposis dolorosa, lipomatosis dolorosa morbus Dercum), is a rare disorder resulting in painful fatty deposits around the upper legs, trunk, and upper arms. The portrait painted of Dercum's disease is very complicated, with many other disorders seen associated with the disease. There are no clear pathological mechanisms known, although it is suspected that there is either a metabolic or autoimmune component involved.

Evidence of increased microvessel density and activation of the hypoxia pathway in tumours from the hereditary leiomyomatosis and renal cell cancer syndrome.

The Mendelian tumour syndromes hereditary leiomyomatosis and renal cell cancer (HLRCC) and hereditary paragangliomatosis with phaeochromocytomas (HPGL) result from mutations in nuclear genes (FH and SDHB/C/D, respectively) that encode Krebs cycle enzymes. HPGL tumours are highly vascular and there is evidence that inactivation of SDH leads to activation of the hypoxia/angiogenesis pathway. In contrast, uterine leiomyomas are not generally regarded as particularly vascular lesions.

The TCA cycle and tumorigenesis: the examples of fumarate hydratase and succinate dehydrogenase.

It is well documented that disturbances in mitochondrial function are associated with rare childhood disorders and possibly with many common diseases of ageing, such as Parkinson's disease and dementia. There has also been increasing evidence linking mitochondrial dysfunction with tumorigenesis. Recently, heterozygous germline mutations in two enzymes of the Krebs tricarboxylic acid cycle (TCA cycle) have been shown to predispose individuals to tumours.

Genomic organization and embryonic expression of Igsf8, an immunoglobulin superfamily member implicated in development of the nervous system and organ epithelia.

Igsf8 is an immunoglobulin protein that binds to the tetraspanin molecules, CD81 and CD9. We describe the genomic organization of mouse and human Igsf8, and reveal a dynamic expression pattern during embryonic and fetal development. Igsf8 is first expressed at E9.