Identification and characterization of DSPIa, a novel isoform of human desmoplakin

Rita M. Cabral, Hong Wan, Clare L. Cole, Dominic J. Abrams, David P. Kelsell, Andrew P. South

    Research output: Contribution to journalArticle

    15 Citations (Scopus)

    Abstract

    Desmoplakin is a ubiquitous component of desmosomes and desmosome-like structures, such as the cardiomyocyte area composita. Two major isoforms, desmoplakin I (DSPI) and desmoplakin II (DSPII) are encoded by alternative mRNA transcripts differentially spliced from the same gene. The resulting proteins are identical in amino acid sequence with the exception that DSPII contains only one third of the central alpha-helical rod domain present in DSPI. Here we describe a novel minor isoform of desmoplakin that is also produced by alternative splicing of the desmoplakin gene and that we name desmoplakin Ia (DSPIa). DSPIa is an alternatively spliced DSPI mRNA with a unique splice donor site that is 90% homologous to and downstream of the DSPII specific donor. The resulting DSPIa mRNA is in-frame and encodes a protein that has a central alpha-helical rod domain of intermediate size and that is 156 amino acids larger than DSPII and 443 amino acids smaller than DSPI. We demonstrate, through recombinant expression and short interfering RNA knockdown, that the DSPIa protein is readily detectable, albeit at substantially lower levels than the dominant isoforms, DSPI and DSPII. DSPIa mRNA has a similar tissue distribution to that of DSPI and of DSPII.

    Original languageEnglish
    Pages (from-to)121-129
    Number of pages9
    JournalCell and Tissue Research
    Volume341
    Issue number1
    DOIs
    Publication statusPublished - Jul 2010

    Keywords

    • Desmosome
    • Desmoplakin
    • Isoform
    • Splice site
    • Quantitative polymerase chain reaction
    • Human
    • INTERMEDIATE-FILAMENT NETWORKS
    • STRIATE PALMOPLANTAR KERATODERMA
    • PRE-MESSENGER-RNA
    • DESMOSOMAL PLAQUE
    • COOH TERMINUS
    • WOOLLY HAIR
    • CARDIOMYOPATHY
    • EXPRESSION
    • KERATIN
    • CELLS

    Cite this

    Cabral, R. M., Wan, H., Cole, C. L., Abrams, D. J., Kelsell, D. P., & South, A. P. (2010). Identification and characterization of DSPIa, a novel isoform of human desmoplakin. Cell and Tissue Research, 341(1), 121-129. https://doi.org/10.1007/s00441-010-0989-1