Short communication
Membrane targeting of the small myristoylated protein 2 (SMP-2) in Leishmania major

https://doi.org/10.1016/j.molbiopara.2013.05.005Get rights and content

Highlights

  • SMP-2 resides in detergent resistant membranes.

  • SMP-2 relies on ionic interactions for stable membrane interaction.

  • N-terminal region of SMP-2 is sufficient for flagellar pocket targeting.

Abstract

Leishmania parasites express three highly conserved small myristoylated proteins (SMPs) that are targeted to distinct membranes. SMP-1 is exclusively found in the flagellum, depending on myristoylation and palmitoylation. In contrast, monoacylated SMP-2 and SMP-4 are localized to the flagellar pocket and plasma membrane, respectively. Here, we demonstrate that unlike SMP-4, SMP-2 resides in detergent resistant membranes, but can be readily solubilized in the presence of high concentrations of salt. We provide evidence that in detergent resistant membranes, SMP-2 forms high molecular weight complexes in vivo. Association with detergent resistant membranes was abrogated in the presence of a C-terminal tag suggesting acylation independent targeting signals. In addition, the N-terminal region of SMP-2 contains sufficient information for membrane targeting, as a GFP-chimera localizes to the flagellar pocket. Thus while the core sequences of the SMPs are highly conserved, individual members have evolved different mechanisms for their diverse membrane localization.

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Acknowledgements

This work was funded under the NHMRC Project and Program Grants. MJM is a NHMRC Principal Research Fellow.

References (20)

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Cited by (2)

  • Potential application of small myristoylated protein-3 evaluated as recombinant antigen and a synthetic peptide containing its linear B-cell epitope for the serodiagnosis of canine visceral and human tegumentary leishmaniasis

    2019, Immunobiology
    Citation Excerpt :

    In this study, SMP-3 presented a 2.48-time reduction in their expression content, when parasites were in vitro cultured for 150 days. Leishmania parasites express a conserved family of small myristoylated proteins (SMPs), which share an identical central domain but contain differential acylation signals and distinct C-terminal subdomains, being target to distinct regions of the plasma membrane including the cell body, flagellum and flagellar pocket (Tull et al., 2012; Heng et al., 2013). The most of SMPs appear to have unknown function in Leishmania (Tull et al., 2004); however, some family proteins, such as SMP-1, showed to be required for flagellar function, since the inhibition of the expression of this protein resulted in flagellum retraction and uncoordinated movements by parasites (Tull et al., 2010).

1

Current address: Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, United Kingdom.

2

Equal senior authors.

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