ABSTRACT
Although most extraskeletal myxoid chondrosarcomas (EMC) are cytogenetically characterized by the translocation t(9;22)(q22;q12), another subset has recently been identified carrying a t(9;17)(q22;q11). Whereas the t(9;22) is known to result in fusion of the CHN (TEC) gene from 9q22 with the EWS gene from 22q12, creating a chimeric EWS/CHN, the genes involved in the t(9;17) of EMC are unknown. We examined two EMC with t(9;17)(q22;q11) and found that the CHN gene was recombined with the RBP56 gene from 17q11 to generate a chimeric RBP56/CHN. RBP56 has not previously been shown to be involved in tumorigenesis but it encodes a putative RNA-binding protein similar to the EWS and FUS (TLS) proteins known to play a pathogenetic role in several sarcomas. The presence of the RBP56/CHN chimeric gene in EMC with t(9;17)(q22;q11) shows that the N-terminal parts of EWS and RBP56 have similar oncogenic potential making them pathogenetically equivalent in oncoproteins arising from fusions with certain transcription factors.
Subject(s)
Artificial Gene Fusion , Chondrosarcoma/genetics , Chromosomes, Human, Pair 17 , DNA-Binding Proteins/genetics , Nerve Tissue Proteins , Nuclear Proteins/genetics , TATA-Binding Protein Associated Factors , Transcription Factors/genetics , Translocation, Genetic , Amino Acid Sequence , Base Sequence , Chromosomes, Human, Pair 9 , Humans , Molecular Sequence Data , Receptors, Steroid , Receptors, Thyroid HormoneABSTRACT
TFG was discovered as a fusion partner of NTRK1 in human papillary thyroid carcinoma. We assembled the mouse TFG cDNA from EST sequences and 5' end RACE product, identified full coding length TFG EST clones in pig (c17b07) and Schistosoma mansoni (SMNAS62), and analyzed the genomic structure of TFG in Caenorhabditis elegans (Y63D3A). The protein sequences of mouse, pig, and S. mansoni TFG are highly homologous to human TFG. The C. elegans sequence has diverged, but its predicted secondary structure is remarkably conserved. Human, mouse, and C. elegans TFG contain a putative trimeric N-terminal coiled-coil domain, glycosylation, myristylation, and phosphorylation sites, and SH2- and SH3-binding motifs. The SH2-binding motif is absent in C. elegans TFG. The expression of TFG does not vary among 7, 11, 15, and 19 day mouse embryonal stages. In situ hybridization with a TFG probe in 10, 5-day whole mouse embryos showed preferential staining of the limb buds, branchial arches, nasal processes, and brain, and weak staining of the primitive spinal cord and dorsal root ganglia.
Subject(s)
Caenorhabditis elegans Proteins , Caenorhabditis elegans/genetics , Proteins/genetics , Amino Acid Sequence , Animals , Base Sequence , Caenorhabditis elegans/chemistry , Chromosome Mapping , DNA, Complementary/genetics , Embryo, Mammalian/metabolism , Embryo, Nonmammalian , Expressed Sequence Tags , Gene Expression Regulation, Developmental , Genes, Helminth , Glycosylation , Humans , Mice , Molecular Sequence Data , Phosphorylation , Protein Structure, Secondary , Proteins/chemistry , RNA, Messenger/metabolism , Schistosoma mansoni/chemistry , Schistosoma mansoni/genetics , Sequence Homology, Amino Acid , Swine/genetics , src Homology Domains/geneticsABSTRACT
Clone 120041 was selected from the EST database for sequence similarity to DEK and SET proteins rearranged in leukemias. The ends of the cDNA were isolated by RACE technique. The assembled cDNA encodes an LRR-containing protein of 251 amino acids designated APRIL (acidic protein rich in leucines). APRIL has high similarity to human pp32, also named PHAPI (bovine I[PP2A]1), and to rat LANP, respectively. APRIL shows tissue-specific expression as shown by Northern blot analysis. It was localized to 15q25 by FISH.
Subject(s)
Chromosomes, Human, Pair 15 , Neuropeptides/genetics , Nuclear Proteins/genetics , Amino Acid Sequence , Animals , Base Sequence , Binding Sites , Casein Kinase II , Chromosome Mapping , Cyclic AMP-Dependent Protein Kinases/metabolism , Gene Expression , Humans , Molecular Sequence Data , Phosphorylation , Protein Serine-Threonine Kinases/metabolism , Rats , Tumor Cells, CulturedABSTRACT
Homology searches in the Expressed Sequence Tag Database were performed using SPYGQ-rich regions as query sequences to find genes encoding protein regions similar to the N-terminal parts of the sarcoma-associated EWS and FUS proteins. Clone 22911 (T74973), encoding a SPYGQ-rich region in its 5' end, and several other clones that overlapped 22911 were selected. The combined data made it possible to assemble a full-length cDNA sequence. This cDNA sequence is 1677 bp, containing an initiation codon ATG, an open reading frame of 400 amino acids, a poly(A) signal, and a poly(A) tail. We found 100% identity between the 5' part of the consensus sequence and the 598-bp-long sequence named TFG. The TFG sequence is fused to the 3' end of NTRK1, generating the TRK-T3 fusion transcript found in papillary thyroid carcinoma. The cDNA therefore represents the full-length transcript of the TFG gene. TFG was localized to 3q11-q12 by fluorescence in situ hybridization. The 3' and the 5' ends of the TFG cDNA probe hybridized to a 2.2-kb band on Northern blot filters in all tissues examined.
Subject(s)
Proteins/genetics , Thyroid Neoplasms/genetics , Amino Acid Sequence , Base Sequence , Chromosome Mapping , Chromosomes, Human, Pair 3/genetics , Cloning, Molecular , DNA, Complementary/genetics , Gene Expression , Humans , In Situ Hybridization, Fluorescence , Molecular Sequence DataABSTRACT
FUS (TLS) was first identified as the 5'-part of a fusion gene with CHOP (GADD153, DDIT3) in myxoid liposarcomas with t(12; 16)(q13; p11). Homologies were found with the EWS oncogene, which is rearranged in Ewing sarcomas and other neoplasias. The genomic structure of FUS shows extensive similarities with that of EWS, but the exon/intron structures differ in the 5' parts, and overall FUS is smaller than EWS. Exon 3 of FUS corresponds to exons 3 and 4 in EWS. FUS exons 4-6 correspond to EWS exons 5-8. Exons 7 to 15 of FUS are very similar to those in EWS, although the EWS exons are larger than the corresponding FUS exons. FUS and EWS were expressed in all tissues investigated. The transcripts were stable within the 160-min half-life experiments. No or little variation in FUS or EWS expression was seen when resting lymphocytes were activated. These observations indicate that FUS and EWS belong to the housekeeping type of genes. This view is supported by the presence of the housekeeping gene type of promoter region in both genes.