JTB: A novel membrane protein gene at 1q21 rearranged in a jumping translocation

Abstract

1q21 is frequently involved in di erent types of translocation in many types of cancers. Jumping translocation (JT) is an unbalanced translocation that comprises ampli®ed chromosomal segments jumping to various telomeres. In this study, we identi®ed a novel gene human JTB (Jumping Translocation Breakpoint) at 1q21, which fused with the telomeric repeats of acceptor telomeres in a case of JT. hJTB (human JTB) encodes a trans-membrane protein that is highly conserved among divergent eukaryotic species. JT results in a hJTB truncation, which potentially produces an hJTB product devoid of the trans-membrane domain. hJTB is located in a gene-rich region at 1q21, called EDC (Epidermal Di erentiation Complex). This is the ®rst report identifying the gene involved in unbalanced translocations at 1q21.

Jumping translocation in acute leukemia of myelomonocytic lineage: a case report and review of the literature

“…In two recent reports of JT, it has been shown that the telomeric sequences were maintained. 12,20 In our case, no telomeric hybridization was found on the recipients. It has been suggested that transformation of myelodysplastic syndrome is associated with excessive telomere shortening which in itself favors recombinations.…”

“…The JT breakpoint is sometimes located in regions known to contain DNA repetitive sequences, such as centromeres or the pericentromeric heterochromatin region. Nevertheless, the breakpoint may be observed in other regions as illustrated by the recent report of Hatakeyama et al 20 which identified a novel human gene JTB at 1q21 encoding a transmembrane protein. Three other donor chromosomes have been reported: 7q in a case of lymphoid blast crisis of CML, 3q and 11q in other cases of AML.…”

Prognostic value of chromosome 1q21 gain by fluorescent in situ hybridization and increase CKS1B expression in myeloma

“…Consistent with this, a large number Chromosome 1q21 copy change and prognosis in myeloma R Fonseca et al of candidate genes in the 1q21 region (e.g., BCL9, MCL1, CKS1B and MUC1) have been pathogenically implicated in MM and other malignancies. 9,[28][29][30][31][32][33][34][35][36][37] More recently, integrated analysis of high-resolution array comparative genomic hybridization and GEP identified a high priority minimal region of DNA copy number change on 1q21. This 10 Mb region contain several genes including the aforementioned CSK1B, BCL9 and MCL1.…”

Characterization of Jumping translocation breakpoint (JTB) gene product isolated as a TGF-β1-inducible clone involved in regulation of mitochondrial function, cell growth and cell death

“…JTB was first identified as an open reading frame from the sequence near a fusion point at 1q21 translocated to telomeric repeats of acceptor telomeres in a case of jumping translocation and postulated to encode a protein of 16.4 kDa (Hatakeyama et al, 1999). An analysis of the protein structure revealed distinctive stretches in the Nand C-terminal regions (Hatakeyama et al, 1999).…”

“…JTB was first identified as an open reading frame from the sequence near a fusion point at 1q21 translocated to telomeric repeats of acceptor telomeres in a case of jumping translocation and postulated to encode a protein of 16.4 kDa (Hatakeyama et al, 1999). An analysis of the protein structure revealed distinctive stretches in the Nand C-terminal regions (Hatakeyama et al, 1999). The N-terminal stretch consisting of highly hydrophobic amino acids supposedly functions as a signal sequence for secretion of the polypeptide or for recruitment to membrane compartments, being processed and removed during the process.…”