A Protein Palmitoylation Cascade Regulates Microtubule Cytoskeleton Integrity inPlasmoidum

Posted: 2020-05-20   Visits: 10

AbstractMorphogenesis of many protozoans depends on a polarized establishment of cytoskeletal structures. In malaria‐causing parasites, this can be observed when a round zygote develops into an elongated motile ookinete within the mosquito stomach. This morphogenesis is mediated by the pellicle cytoskeletal structures, including the inner membrane complex (IMC) and the underlying subpellicular  microtubules (SPMs). How the parasite maintains the IMC‐SPM connection and  establishes a dome‐like structure of SPM to support cell elongation is unclear. Here, we show that palmitoylation of N‐terminal cysteines of two IMC proteins  (ISP1/ISP3) regulates the IMC localization of ISP1/ISP3 and zygote‐to‐ookinete  differentiation. Palmitoylation of ISP1/ISP3 is catalyzed by an IMC‐residing  palmitoyl‐S‐acyl‐transferase (PAT) DHHC2. Surprisingly, DHHC2 undergoes  self‐palmitoylation at C‐terminal cysteines via its PAT activity, which controls  DHHC2 localization in IMC after zygote formation. IMC‐anchored ISP1 and ISP3  interact with microtubule component β‐tubulin, serving as tethers to maintain  the proper structure of SPM during zygote elongation. This study identifies the  first PAT–substrate pair in malaria parasites and uncovers a protein  palmitoylation cascade regulating microtubule cytoskeleton.

Source: https://life.xmu.edu.cn/lifeen/2020/0519/c8819a402204/page.htm

Link: https://www.embopress.org/doi/full/10.15252/embj.2019104168