Genomic structure and tissue-specific expression of human and mouse genes encoding homologues of the major bovine seminal plasma proteins

Sperm capacitation is a maturation event that takes place in the female reproductive tract and is essential for fertilization. A family of phospholipid-binding proteins present in bovine seminal plasma (BSP proteins) binds the sperm membrane at ejaculation and promotes bovine sperm capacitation. Homologues of these proteins have also been isolated from boar, ram, goat, bison and stallion seminal fluid, suggesting that BSP proteins and their homologues are conserved among mammals. However, there have been no reports on BSP-homologous proteins in mice and humans to date. A search of the mouse and human genomes, using the nucleic acid sequences of BSP proteins, revealed the presence of three BSP-like sequences in the mouse genome, named mouse BSP Homologue 1 (mBSPH1), mBSPH2 and mBSPH3, and one sequence in the human genome (hBSPH1). Mouse epididymal expressed sequence tags corresponding to partial sequences of mBSPH1 and mBSPH2 were identified. The entire complementary DNA (cDNA) sequences of mBSPH1 and mBSPH2 from mouse epididymis and hBSPH1 from human epididymis were obtained by 5'-/3'-rapid amplification of cDNA ends (RACE) and encode predicted proteins containing two tandemly repeated fibronectin type II domains, which is the signature of the BSP family of proteins. Using RT-PCR, it was revealed that mBSPH1, mBSPH2 and hBSPH1 mRNA are expressed only in the epididymis. Expression of mBSPH3 was not detected in any tissue and probably represents a pseudogene. This work shows, for the first time, that BSP homologues are expressed in mouse and human and may be involved in sperm capacitation in these species.     

Antibodies to CRMP3-4 associated with limbic encephalitis and thymoma

We present a case with subacute limbic encephalitis (LE) and thymoma. Neither classical onconeural antibodies nor antibodies to voltage gated potassium channels (VGKC) were detected, but the serum was positive for anti-glutamic acid decarboxylase (GAD). The patient serum also stained synaptic boutons of pyramidal cells and nuclei of granule cells of rat hippocampus. The objective of the study was to identify new antibodies associated with LE. Screening a cDNA expression library identified collapsin response mediator protein 3 (CRMP3), a protein involved in neurite outgrowth. The serum also reacted with both CRMP3 and CRMP4 by Western blot. Similar binding pattern of hippocampal granule cells was obtained with the patient serum and rabbit anti-serum against CRMP1-4. The CRMP1-4 antibodies stained neuronal nuclei of a biopsy from the patient's temporal lobe, but CRMP1-4 expression in thymoma could only be detected by immunoblotting. Absorption studies with recombinant GAD failed to abolish the staining of the hippocampal granule cells. Our findings illustrate that CRMP3-4 antibodies can be associated with LE and thymoma. This has previously been associated with CRMP5.     

丙型肝炎病毒NS3区优势表位基因的克隆和高效表达研究

丙型肝炎病毒（ＨＣＶ）的Ｃ３３ｃ基因编码蛋白是ＨＣＶ抗体检测中所需的重要抗原。应用打点杂交法得到了来源于３例病人的８个Ｃ３３ｃ的克隆，并从中挑选出能在大肠杆菌中高效表达的克隆─—ｐＫＨ２６。该重组质粒中的插入片段与ＨＣＶ－Ｊ的核苷酸同源性为９２．６％，所编码氨基酸的同源性为９５．９％，属于中国主要的ＨＣＶ流行株，它可通过温度变化这种简单、方便、经济的方式进行诱导表达，得到以天然蛋白形式存在的具有良好免疫学活性的表达产物，表达蛋白产量可占整个细菌蛋白的１５％以上。由于不含有融合蛋白，用于抗－Ｃ３３ｃ的检测特异性高，是建立诊断ＨＣＶ感染方法的良好原材料。     

ATP‐binding cassette transporter A1 (ABCA1) promotes arsenic tolerance in human cells by reducing cellular arsenic accumulation

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