The human NTT gene: identification of a novel 17-kb noncoding nuclear RNA expressed in activated CD4+ T cells.
We describe the cloning and characterization of the NTT gene (noncoding transcript in T cells), identified by differential display RT-PCR based on the differential presence of its transcript in a subset of activated, human CD4+ T-cell clones. The full-length cDNA and genomic sequences were cloned and found to produce a 17-kb transcript that is polyadenylated, but is not spliced. Consistent with the transcript's nuclear predominance, NTT has no open reading frame larger than 270 bp. It is transcribed in a select subset of CD4+ T-cell clones propagated in vitro. Its transcription can also be induced in freshly isolated T cells by in vitro activation with PHA or with PMA and ionomycin. In vivo, NTT transcripts are found only in activated, but not resting, T cells. Transcripts were absent in a variety of lymphoid cell lines and transformed lines from other tissues. NTT is a new member of the small group of genes including XIST (X-specific transcript), H19, and IPW (imprinted gene in the Prader-Willi syndrome region), which are transcribed but not translated, and may have a role in the regulation of neighboring genes. XIST, H19, and IPW exhibit monoallelic expression, but both NTT alleles are expressed in CD4+ T-cell clones. Southern blot and fluorescence in situ hybridization analyses show that NTT is a single-copy gene residing in chromosome 6q23-q24, near the interferon-gamma receptor gene (IFN-gamma R). Their proximity and shared expression pattern suggest a possible functional relationship.
Liu
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AY
Department of Molecular Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Torchia
B S
BS
Migeon
B R
BR
Siliciano
R F
RF
D000483:Alleles; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D002874:Chromosome Mapping; D002896:Chromosomes, Human, Pair 6; D003001:Cloning, Molecular; D018076:DNA, Complementary; D015870:Gene Expression; D015894:Genome, Human; D006801:Humans; D006822:Hybrid Cells; D017404:In Situ Hybridization, Fluorescence; D008213:Lymphocyte Activation / Q000235:genetics; D008969:Molecular Sequence Data; D011061:Poly A / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D015138:RNA, Nuclear / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D016415:Sequence Alignment; D014158:Transcription, Genetic
D018076:DNA, Complementary; D012333:RNA, Messenger; D015138:RNA, Nuclear; D011061:Poly A