Recently, cDNA sequences have been reported for both human and murine tumor necrosis factor (TNF; cachectin). The coding region of the TNF genes is highly conserved between man and mouse; 80% homology is apparent at the amino acid level. We now observe that a 33-nucleotide sequence, comprised entirely of A and T residues and located in the 3'-untranslated region, is conserved in toto in the murine and human TNF mRNAs. Since the 3'-untranslated region is normally not conserved, we reasoned that this sequence might play a regulatory role. We identified a consensus sequence (TTATTTAT) present in the 3'-untranslated region of both human and mouse TNF mRNAs, as well as the mRNAs encoding human lymphotoxin, human colony stimulating factor, human and mouse interleukin 1, human and rat fibronectin, and most of the sequenced human and mouse interferons. All of these mRNAs, except the lymphotoxin mRNA, lack homology to the TNF mRNAs in the coding region. The consensus sequence is uncommon among mammalian mRNAs in general, but it appears with a frequency greater than chance alone would dictate, suggesting that it may serve a specific regulatory function among the mRNAs in which it is found. It is particularly prevalent among mRNAs encoding proteins related to the inflammatory response.
The nucleotide sequence of molecular clones of DNA from a retrovirus, ARV-2, associated with the acquired immune deficiency syndrome (AIDS) was determined. Proviral DNA of ARV-2 (9737 base pairs) has long terminal repeat structures (636 base pairs) and long open reading frames encoding gag (506 codons), pol (1003 codons), and env (863 codons) genes. Two additional open reading frames were identified. Significant amino acid homology with several other retroviruses was noted in the predicted product of gag and pol, but ARV-2 was as closely related to murine and avian retroviruses as it was to human T-cell leukemia viruses (HTLV-I and HTLV-II). By means of an SV-40 vector in transfected simian cells, the cloned gag and env genes of ARV-2 were shown to express viral proteins.
The inactivation of growth suppressor genes appears to play a major role in the malignant process. To assess whether protein phosphotyrosyl phosphatfises (protein-tyrosine-phosphate phosphohydrolase, EC 3.1.3.48) function as growth suppressors, we have isolated a cDNA clone encoding human protein phosphotyrosyl phosphatase 1B for structural and functional characterization. The translation product deduced from the 1305-nucleotide open reading frame predicts a protein containing 435 amino acids and having a molecular mass of 49,966 Da. The amino-terminal 321 amino acids deduced from the cDNA sequence are identical to the empirically determined sequence of protein phosphotyrosyl phosphatase 1B
In the course of our screening for small molecule modulators of erythropoietin gene expression, two novel sesquiterpene tropolones and pycnidone were isolated from a culture of OS-F69284 (ATCC 74390). Their structures were elucidated by extensive 1H and 13C NMR spectroscopic studies and chemical reactions. These compounds induced erythropoietin gene expression 5-fold at a concentration of 1-1.6 microM.
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