Characterization of the human NIPSNAP1 gene from 22q12: a member of a novel gene family

Rapid progress in sequencing of human and other genomes allows high-resolution analysis of their gene content on the basis of comparison between species. We have used a combined computer and biochemical approach to characterize 135 kb of human genomic sequence from 22q12 and discovered a new 10 exon gene, termed NIPSNAP1, located between the neurofibromatosis type 2 and the pK1.3 genes. The NIPSNAP1 gene spans 26 kb of genomic sequence and shows two large introns in the 5′-region. All exon–intron junctions contain the gt/ag consensus splice site. The putative promoter of the NIPSNAP1 gene is TATA-less and resides in a GC-rich island characteristic of housekeeping genes. The NIPSNAP1 mRNA is 2.1 kb, is expressed ubiquitously at variable levels, with the highest expression in liver, is terminated by an uncommon ATTAAA polyadenylation site, and is capable of encoding a 284-amino-acid protein. This NIPSNAP1 protein has a strong sequence similarity limited to the central portion of a hypothetical protein (acc. P34492) from chromosome III of C. elegans, in which the other portions resemble a 4-nitrophenylphosphatase domain and non-neuronal SNAP25-like protein. Thus, the NIPSNAP1 gene is a member of an evolutionarily well conserved, novel gene family with two members in human and mouse that have now been characterized, and one member in C. elegans. The second human gene, NIPSNAP2, is localized in the vicinity of marker D7S499 on chromosome 7. Although the function of the NIPSNAP protein family is unknown, clues about its role may reside in the co-expression of the C. elegans orthologue, within an operon encoding protein motifs known to be involved in vesicular transport.     

Endothelial plasminogen activator inhibitor (PAI): a new member of the Serpin gene family.

A human endothelial cDNA expression library, based on the Escherichia coli plasmid pUC9, was screened with a heterologous antibody raised against purified bovine aortic endothelial plasminogen activator inhibitor (PAI). A synthetic oligonucleotide, derived from a partial PAI cDNA expression clone, was used to select a full-length PAI cDNA, the size of which coincides with the length of PAI mRNA (approximately 2350 nucleotides) as determined by Northern blot analysis. The authenticity of full-length PAI cDNA is demonstrated by the expression of biologically active PAI both in lysates of transformed E. coli cells and in conditioned media of mouse Ltk- cells, transfected with PAI cDNA inserted into vector pSV2. Analysis of the de novo synthesized anti-plasminogen activator activity, employing reverse fibrin autography, shows that transfected mouse Ltk- cells synthesize a polypeptide with a mol. wt identical to that of the native PAI glycoprotein (Mr 52,000), whereas in E. coli an unglycosylated, active product with a mol. wt of 43,000 is made. The amino acid sequence, derived from the determined nucleotide sequence, shows that pre-PAI consists of 402 amino acids. It is proposed that the mature PAI is preceded by a signal peptide of 23 amino acid residues. The amino acid sequence of mature PAI includes three potential asparagine-linked glycosylation sites and lacks cysteine residues. The predicted amino acid sequence reveals significant homology with members of the serine protease inhibitor (Serpin) family, e.g. alpha 1-proteinase inhibitor and antithrombin III.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cloning and characterization of a new member of the T-box gene family

The T-box is a strongly conserved protein domain, 174 to 186 amino acids in length, that binds DNA. Many genes from many species have been shown to encode T-box domain-containing proteins. Here we report the cloning and characterization of a novel T-box gene, TBX21. The human cDNA contains an open reading frame encoding a 535-amino-acid protein with a predicted molecular mass of 58.3 kDa. Except for the T-box sequence, database searches revealed no significant homology to any known sequences at the nucleotide or protein level. In addition to the human cDNA sequence, we report the cDNA sequence of the murine homologue, the structure and organization of the murine Tbx21 gene, and its localization to mouse chromosome 11. TBX21 expression was detected in peripheral blood lymphocytes, spleen, lung, and natural killer cells.     

Characterization of Schistosoma mansoni ATPDase2 gene, a novel apyrase family member

Schistosoma mansoni is a major causative agent of schistosomiasis, which constitutes a severe health problem in developing countries. We have previously described the SmATPDase1 gene, encoding a protein from the external surface of the parasites. In this work, we describe the cloning and characterization of SmATPDase2, a novel CD39-like ATP diphosphohydrolase gene in S. mansoni. In silico analysis of the protein encoded by SmATPDase2 predicts a single N-terminal transmembrane domain similar to that described for secreted human apyrase isoforms. Immuno-colocalization experiments detected both SmATPDase proteins at the S. mansoni adult worm tegument basal and apical membranes, but only SmATPDase2 in the tegument syncytium. SmATPDase2 but not SmATPDase1 protein was detected by Western blot in culture medium supernatants following incubation of adult worms in vitro, indicating that SmATPDase2 was secreted by the parasite to the medium. Taken together these data suggest a non-redundant role for SmATPDase2 in the parasite-host interplay.     

Characterization of a cDNA clone encoding a new species of the nonspecific cross-reacting antigen (NCA), a member of the CEA gene family

To clarify the molecular structures of the nonspecific cross-reacting antigens (NCAs) produced by human granulocytes, we cloned cDNAs from libraries of normal white blood cells. A clone, NCA-W272, was found to code a protein similar to NCA of tumor cells. The protein consisted of a signal peptide (34 aa), domain-N (108 aa), -A1 (92 aa), -B1 (86 aa) and -M (29 aa). Similarity of the amino acid sequence of each domain to that of the tumor NCA was 72, 92, 76 and 79%, respectively. COS-1 cells transfected with an expression vector carrying the cDNA synthesized a 70 kDa glycoprotein, which was reactive with anti-NCA antibody and released from cell surface by phosphatidylinositol-specific phospholipase C. Thus the clone NCA-W272 was indicated to encode a new species of NCA distinct from the tumor NCA.     

Endothelial lipase: a new member of the triglyceride lipase gene family

The triglyceride lipase gene family plays a central role in intestinal lipid absorption, energy homeostasis, lipoprotein metabolism, and atherosclerosis. A new member of this gene family, termed endothelial lipase, was recently reported. The presence of key functional motifs, the endothelial synthesis, the enzymatic profile, and the in-vivo metabolic effects of endothelial lipase suggest that, like other members of this gene family, endothelial lipase may play a role in energy delivery to tissues and in modulating lipoprotein metabolism, and could impact on atherogenesis.     

A human T cell-specific molecule is a member of a new gene family

We have used a cDNA library enriched for T cell-specific sequences to isolate genes expressed by T cells but not by other cell types. We report here one such gene, designated RANTES, which encodes a novel T cell-specific molecule. The RANTES gene product is predicted to be 10 kDa and, after cleavage of the signal peptide, approximately 8 kDa. Of the 68 residues, 4 are cysteines, and there are no sites for N-linked glycosylation. RANTES is expressed by cultured T cell lines that are Ag specific and growth factor dependent. RANTES expression is inducible in PBL by Ag or mitogen. In CTL, expression of RANTES decreases after stimulation with Ag and growth factors. Interestingly, RANTES was not expressed by any T cell tumor line tested. There is significant homology between the RANTES sequence and several other T cell genes, suggesting that they comprise a previously undescribed family of small T cell molecules.     

IL-36 a new member of the IL-1 family cytokines

Interleukin-36 (IL-36) is a pro-inflammatory cytokine which plays an important role in innate and adaptive immunity. IL-36 activates MAPK and NF-kB pathways and is produced by many different cells. This cytokine is a family member of interleukin-1 (IL-1) and plays an important role in the pathophysiology of several diseases. Here we summarise and review the new aspects of this important pro-inflammatory cytokine.     

Identification of a new, unorthodox member of the MAGE gene family.

Several tumor-associated antigen families, such as MAGE, GAGE/PAGE, PRAME, BAGE, and LAGE/NY-ESO-1, exist. These antigens are of particular interest in tumor immunology, because their expression, with exception of testis and fetal tissues, seems to be restricted to tumor cells only. We have identified a novel member of the MAGE gene family, MAGED1. Northern hybridization and RT-PCR demonstrated that the expression level of MAGED1 in different normal adult tissues is comparable to that in testis and fetal liver. Thus, MAGED1 does not possess an expression pattern characteristic of previously identified MAGE family genes, suggesting that the biology of the MAGE-family genes is more complex than previously thought. Chromosome mapping linked MAGED1 to marker AFM119xd6 (DXS1039) on chromosome Xp11.23.