Muscle type-specific expression of Zasp52 isoforms in Drosophila

Department of Biology, McGill University, 1205 Dr. Penfield Avenue, Montreal, Quebec, Canada H3A 1B1.
Gene Expression Patterns (Impact Factor: 1.36). 08/2011; 11(8):484-90. DOI: 10.1016/j.gep.2011.08.004
Source: PubMed

ABSTRACT Zasp52 is a member of the PDZ-LIM domain protein family in Drosophila, which comprises Enigma, ENH, ZASP, Alp, CLP36, RIL, and Mystique in vertebrates. Drosophila Zasp52 colocalizes with integrins at myotendinous junctions and with α-actinin at Z-disks, and is required for muscle attachment as well as Z-disk assembly and maintenance. Here we document 13 Zasp52 splice variants giving rise to six different LIM domains. We demonstrate stage- and tissue-specific expression in different muscle types for Zasp52 isoforms encoding different LIM domains. In particular, LIM1b is expressed only in heart muscle and certain somatic muscles, implying muscle-specific functions in Z-disk assembly or maintenance.

Download full-text


Available from: Frieder Schöck, Dec 24, 2013
  • Source
    • "Drosophila Zasp is spliced even more extensively, with 13 splice variants documented so far (Katzemich et al., 2011). We previously reported that Zasp is involved in the assembly of integrin adhesion sites in Drosophila muscle, that Zasp genetically interacts with aPS2 integrin during muscle attachment, and that in Zasp-deficient flies, embryonic and first larval instar muscles partially detach from myotendinous junctions (Jani and Schöck, 2007). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Integrins are heterodimeric adhesion receptors that link the extracellular matrix (ECM) to the cytoskeleton. Binding of the scaffold protein, talin, to the cytoplasmic tail of β integrin causes a conformational change of the extracellular domains of the integrin heterodimer, thus allowing high-affinity binding of ECM ligands. This essential process is called integrin activation. Here we report that the Z-band alternatively spliced PDZ-motif containing protein (Zasp) cooperates with talin to activate α5β1 integrins in mammalian tissue culture and αPS2βPS integrins in Drosophila. Zasp is a PDZ-LIM domain-containing protein mutated in human cardiomyopathies previously thought to function primarily in assembly and maintenance of the muscle contractile machinery. Notably, Zasp is the first protein shown to co-activate α5β1 integrins with talin and appears to do so in a manner distinct from known αIIbβ3 co-activators.
    Journal of Cell Science 09/2012; 125(23). DOI:10.1242/jcs.103291 · 5.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We highlight recent progress in understanding cadherin and integrin function in the model organism Drosophila. New functions for these adhesion receptors continue to be discovered in this system, emphasising the importance of cell adhesion within the developing organism and showing that the requirement for cell adhesion changes between cell types. New ways to control adhesion have been discovered, including controlling the expression and recruitment of adhesion components, their posttranslational modification, recycling and turnover. Importantly, even ubiquitous adhesion components can function differently in distinct cellular contexts.
    Current opinion in cell biology 08/2012; 24(5):702-12. DOI:10.1016/ · 8.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Z-disc is a critical anchoring point for thin filaments as they slide during muscle contraction. Therefore, identifying components of the Z-disc is critical for fully comprehending how myofibrils assemble and function. In the adult Drosophila musculature, the fibrillar indirect flight muscles accumulate a >200kD Z-disc protein termed Z(210), the identity of which has to date been unknown. Here, we use mass spectrometry and gene specific knockdown studies, to identify Z(210) as an adult isoform of the Z-disc protein Zasp52. The Zasp52 primary transcript is extensively alternatively spliced, and we describe its splicing pattern in the flight muscles, identifying a new Zasp52 isoform which is the one recognized by the Z(210) antibody. We also demonstrate that Zasp52 is required for the association of alpha-actinin with the flight muscle Z-disc, and for normal sarcomere structure. These studies expand our knowledge of Zasp isoforms and their functions in muscle. Given the role of Zasp proteins in mammalian muscle development and disease, our results have relevance to mammalian muscle biology.
    Journal of Biological Chemistry 12/2012; DOI:10.1074/jbc.M112.401794 · 4.57 Impact Factor
Show more