The tal gene undergoes chromosome translocation in T cell leukemia and potentially encodes a helix-loop-helix protein.

Abstract

We have analyzed t(1;14)(p32;q11) chromosome translocations from two patients with T cell acute lymphocytic leukemia. The chromosome 1 breakpoints of these patients lie within a kilobasepair of each other, and thus define a genetic locus (designated tal) involved in T cell oncogenesis. Moreover, we have identified sequences within tal that potentially encode an amphipathic helix‐loop‐helix motif, a DNA‐binding domain found in a variety of proteins that control cell growth and differentiation. The homology domain of tal is especially related to that of lyl‐1, a gene on chromosome 19 that has also been implicated in T cell oncogenesis. Hence, tal and lyl‐1 encode a distinct family of helix‐loop‐helix proteins involved in the malignant development of lymphocytes.

The basic region/helix – loop – helix/leucine zipper domain of Myc proto-oncoproteins: Function and regulation

“…Identical and highly conserved amino acids are indicated in dark and light green, respectively. The basic region sequences were derived from the following references: human c-Myc (Stanton et al, 1983), human N-Myc (Stanton et al, 1986), human L-Myc (DePinho et al, 1987), human Max (Blackwood and Eisenman, 1991), human Mad1 , human Mxi1 (Zervos et al, 1993), murine Mad3 (Hurlin et al, 1995a), murine Mad4 (Hurlin et al, 1995a), human Rox/Mnt (Meroni et al, 1997), human USF (Gregor et al, 1990), human TFE3 (Beckman et al, 1990), human TFEB (Carr and Sharp, 1990, human MyoD (Pearson-White, 1991), human myogenin (Braun et al, 1989), human AP4 (Ou et al, 1994), human E12 (Murre et al, 1989), human TAL1 (Chen et al, 1990), D. melanogaster da (Caudy et al, 1988). (C) Basic region sequences of Myc/Max/Mad family members.…”

p300 functions as a transcriptional coactivator for the TAL1/SCL oncoprotein

“…The TAL1 (or SCL) gene was originally identi®ed from its involvement by a recurrent chromosomal translocation in patients with T-cell acute lymphoblastic leukemia (T-ALL) (Begley et al, 1989a;Chen et al, 1990;Finger et al, 1989). Interstitial deletions that fuse TAL1 coding sequences to the promoter of an upstream gene, SIL (for SCL interrupting locus), were found subsequently to occur with greater frequency than translocations (Aplan et al, 1990;Bernard et al, 1990;Brown et al, 1990).…”

The CD2-scl transgene alters the phenotype and frequency of T-lymphomas in N-ras transgenic or p53 deficient mice

“…The SCL (TAL-1/TCL5) gene was ®rst identi®ed by its involvement in a t(1;14)(p32;q11) chromosomal translocation seen in 3% of childhood T-cell acute lymphoblastic leukemia (T-ALL) (Begley et al, 1989;Finger et al, 1989;Chen et al, 1990). Scl is a member of the basic helix ± loop ± helix (bHLH) family of transcription factors.…”