Disease relevance of SPTB

• The mutations responsible for hereditary elliptocytosis (HE) and its aggravated form, poikilocytosis (HP), lie in the SPTA1 and SPTB gene, already mentioned, and in the EPB41 gene encoding protein 4 [1].
• Frequent de novo monoallelic expression of beta-spectrin gene (SPTB) in children with hereditary spherocytosis and isolated spectrin deficiency [2].
• Women with SPTB are significantly more likely to have acute inflammation in the free membranes, chorionic plate, and cord, and chorionic plate thrombosis, while women with an IPTB are significantly more likely to have chronic inflammation and especially DDLN [3].
• Mutation of a highly conserved residue of betaI spectrin associated with fatal and near-fatal neonatal hemolytic anemia [4].

High impact information on SPTB

• In both peripheral lymphocytes and Jurkat T cells, betaI spectrin and ankyrin associate with CD45 [5].
• In Jurkat T cells, betaI spectrin peptides suppress surface recruitment of CD45 and CD3 and abrogate T cell activation [5].
• In particular, they involve the SPTA1 and SPTB genes that encode erythroid spectrin alpha- and beta-chains, respectively [6].
• A StuI RFLP in the human beta-spectrin gene (SPTB) [7].
• We used SpalphaI-1-156 peptide, a well-characterized model peptide of the alphaN-terminal region of erythrocyte spectrin, and SpalphaII-1-149, an alphaII brain spectrin model peptide similar in sequence to SpalphaI-1-156, to study their association affinities with a betaI-spectrin peptide, SpbetaI-1898-2083, by isothermal titration calorimetry [8].

Biological context of SPTB

• Our results demon strate the following: (1) The promoter regions of EPB3 and ELB42 are extensively methylated in DNA from human peripheral blood mononuclear cells, but the SPTB promoter is totally unmethylated [9].
• Whereas the human SPTB promoter conforms to expectations in that it is unmethylated and fully active throughout erythroid development, high levels of promoter methylation correlate with promoter activity for the EPB3 and ELB42 genes during their sequential activation in erythrocyte differentiation [9].
• The results of this analysis place the translocation breakpoint on the long arm of chromosome 14 between the proximal marker SPTB and the distal marker D14S77, narrowing the chromosomal translocation breakpoint to a region of approximately 7 cM [10].
• Linkage analysis using two microsatellite markers (D14S63 and D14S271) very close to the beta-spectrin gene (SPTB) showed that HS co-segregated with alleles of these microsatellite markers and the linkage between the marker and HS was statistically significant [11].
• Nulliparas and women with previous term births each had about 64% SPTB and 36% IPTB [3].

Anatomical context of SPTB

• (c) SPTB remains unmethylated in human DNA from UT-7/EPO cells and from cultured erythroblasts [9].
• We also investigated methylation profiles in peripheral blood mononuclear cells from patients with red cell membrane diseases, such as complete protein 4.2 deficiency due to ELB42 mutations, hereditary spherocytosis with EPB3 mutations, and hereditary elliptocytosis with SPTB mutations [12].
• Using a cDNA probe, we had previously assigned the gene for human erythrocyte beta-spectrin (SPTB) to chromosome 14 based upon analysis of its segregation in panels of human x rodent somatic cell hybrids (Winkelmann et al., 1988) [13].

Associations of SPTB with chemical compounds

• The number of 5'-CG-3' dinucleotides was the most abundant in SPTB and ANK1, much less in EPB3, and the least in ELB42 [12].
• In 2005, 67% of respondents used progesterone to prevent SPTB, compared to 38% in 2003 (P < .001) [14].

Other interactions of SPTB

• 1. Whereas in HS, the SPTA1 and SPTB gene mutations tend to abolish the synthesis of the corresponding chains, in HE/HP, they hinder spectrin tetramerization [1].
• In the DNA of peripheral blood mononuclear cells from healthy individuals, the promoter regions of EPB3 and ELB42 were extensively methylated, but the SPTB and ANK1 promoters were totally unmethylated [12].

Analytical, diagnostic and therapeutic context of SPTB

• Assignment of the gene for beta-spectrin (SPTB) to chromosome 14q23----q24.2 by in situ hybridization [13].

References