Ahmed Lab

  • Fusion gene LRTOMT Project

    Characterization of the Fusion Gene LRTOMT – One Gene, Two Proteins

    Recently, we reported that mutations of LRTOMT are associated with profound nonsyndromic hearing loss at the DFNB63 locus on human chromosome 11q13.3. LRTOMT has two alternative reading frames and encodes two different proteins, LRTOMT1 and LRTOMT2, that are detected by Western blot analysis.

    During evolution, novel transcripts can arise through partial or complete coalescence of genes.  In the report, we provide evidence that LRTOMT evolved in the primate lineage from the fusion of two neighboring ancestral genes, which exist as separate genes (Lrrc51 and Tomt) in rodents.

    LRTOMT is the first example, to our knowledge, of a human gene that exhibits transcription mediated gene fusion and has dual reading frames (although the latter phenomenon is predicted to be common, but understudied, in primates) and may have implication for understanding hereditary disorders.

    The selective pressures and adaptive benefits, if any, that give rise to a fusion gene such as LRTOMT are yet to be determined.  Transcription-induced chimerism of two neighboring genes can generate bifunctional, multidomain proteins.  Another benefit may be the tight co-expression of functionally related proteins, which might be true for LRTOMT1 and LRTOMT2 (the mouse orthologs, Lrrc51and Tomt, are both expressed in hair cells).  Our current studies focus on identifying the role – or roles – played by this fusion gene.

 
  • Lrrc51 and Tomt, mouse orthologs.

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    Lrrc51 and Tomt, mouse orthologs.

    Lrrc51 and Tomt, mouse orthologs.