Probability (GAS) of Function in Spermatogenesis |
0.00372042
The probability was calculated by GAS algorithm, ranging from 0 to 1. The closer it is to 1, the more possibly it functions in spermatogenesis. |
Abstract of related literatures |
1. A cDNA clone was isolated from a mouse pre-B cell line, the sequence of which has a very high homology with rat and human thymosin beta 4 genes. However, the mouse clone has an insertion of 98 bp relative to the published rat and human sequences upstream of the coding region. By isolation of a second set of clones from a different cDNA library and by cloning a PCR amplified region of mouse genomic DNA it was confirmed that the insertion is not a cloning artifact. Furthermore, it was shown by RNase protection assays with RNA from the pre-B cell line that two sizes of thymosin beta 4 mRNA exist, a long form containing the 98 nucleotide insertion, and a short form that corresponds to the known rat and human mRNA. The short form is about 50 times more abundant than the long form. Analysis of genomic DNA by sequencing and Southern blotting revealed that both forms are encoded by a single gene in the mouse. The two forms of mRNA arise by differential RNA splicing; the long mRNA contains three separate exons, whereas the short mRNA is missing exon 2. The long mRNA is present in two different pre-B cell lines, spleen and thymus, but could not be detected in brain, liver, and kidney. It is possible that the longer mRNA, which encodes a hydrophobic NH2-extension of six additional amino acids, plays a role in lymphocyte function or development. In contrast to the mouse which has a single thymosin beta 4 gene, rat and human have multiple homologs. Most or all of these also contain sequences that cross-hybridize with the newly discovered exon 2. A polymorphic thymosin beta 4 gene has been found in human DNA. PMID: [2351831]
2. Prothymosin alpha [corrected] (ProT alpha) and thymosin beta 4 [corrected] (T beta 4) were isolated from murine thymus and characterized by microsequence analysis. Murine T beta 4 has an identical sequence to bovine T beta 4, whereas murine ProT alpha is highly homologous to rat Pro T alpha. Murine Pro T alpha differs from rat Pro T alpha at two positions, Glu100 and Asp108 of the rat sequence are substituted by aspartic and glutamic acid, respectively, in murine Pro T alpha. The amount of Pro T alpha in murine thymus was found to be reduced after in vivo treatment with staphylococcal enterotoxin B [corrected] (SEB), a superantigen which stimulates T cells bearing specific V beta receptors. Results from the anti-SRBC (sheep erythrocyte) plaque-forming cell assay showed that the antibody response of the spleen cells from these animals was also suppressed. On the other hand, the amount of T beta 4 was not changed significantly. Our studies suggest that the suppression of SEB on antibody response correlates with the depression of Pro T alpha production in the thymus. PMID: [2226839]
3. Thymosin beta 4 (T beta 4) is an actin monomer sequestering protein that may have a critical role in modulating the dynamics of actin polymerization and depolymerization in nonmuscle cells. Its regulatory role is consistent with the many examples of transcriptional regulation of T beta 4 and of tissue-specific expression. Furthermore, lymphocytes have a unique T beta 4 transcript relative to the ubiquitous transcript found in many other tissues and cells. To determine how T beta 4 gene expression is regulated and how the alternative transcripts are derived, we cloned the mouse T beta 4 gene. We established that there is a single mouse T beta 4 gene and found that the lymphoid-specific transcript is generated by extending the ubiquitous exon 1 with an alternate downstream splice site. The transcription start site is defined by primer extension analysis, and the 5'-flanking region has many of the characteristics of a promoter. It is pyrimidine-rich and contains typical promoter elements, including a GC box, an initiator site, and consensus transcription factor binding sites. The mouse T beta 4 gene locus (Ptmb4) is located by interspecific backcross mapping to the distal region of the mouse X chromosome, linked to Btk and Gja6. PMID: [8838802]
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