Inhibitors of ubiquitin-dependent proteolysis can delay programmed cell death of adult intersegmental muscles in the moth Manduca sexta

Authors

  • Ronald J. Bayline,

    Corresponding author
    1. Department of Biology, Washington and Jefferson College, Washington, Pennsylvania
    2. Field of Neurobiology and Behavior, Cornell University, Ithaca, New York
    • Washington and Jefferson College, 60 South Lincoln Street, Washington, PA 15301
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  • Derek M. Dean,

    1. Field of Genetics and Development, Cornell University, Ithaca, New York
    Current affiliation:
    1. Department of Biology, TBL 110, Williams College, Williamstown, MA 01267
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  • Ronald Booker

    1. Field of Neurobiology and Behavior, Cornell University, Ithaca, New York
    2. Field of Genetics and Development, Cornell University, Ithaca, New York
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Abstract

In the moth Manduca sexta, intersegmental muscles (ISMs) undergo rapid programmed cell death (PCD) within 48 hr of adult emergence. ISM PCD involves ubiquitin-dependent proteasomal degradation accompanied by the down-regulation of expression of actin genes and the up-regulation of degradative gene expression such as ubiquitin. Hemin chloride and N-acetyl-leu-leu-norleucinal (ALLN), both inhibitors of proteasomal activity, administered before adult emergence delayed PCD for up to 5 days in ISMs maintained from the larval stage, such as the dorsal internal medial muscle in abdominal segment 4 (DIM-A4). ISMs that developed during metamorphosis from respecified larval muscles such as the DIM-A2 were less dramatically affected. The increase in polyubiquitinated proteins and the decrease in actin mRNA expression accompanying maintained ISM PCD were delayed after inhibitor application. No changes were detected in respecified ISMs. These results reveal a regulatory role for proteasomal activity in an early stage of maintained ISM cell death. Developmental Dynamics 233:445–455, 2005. © 2005 Wiley-Liss, Inc.

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