Both the N- and C- terminal regions of the Chlamydial inclusion protein D (IncD) are required for interaction with the pleckstrin homology domain of the ceramide transport protein CERT

Journal Article · Thu Nov 15 04:00:00 EST 2018 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2018.09.168· OSTI ID:23107752

Kumagai, Keigo ^[1]; Elwell, Cherilyn A. ^[2]; Ando, Shuji ^[3]; Engel, Joanne N. ^[2]; Hanada, Kentaro ^[1]

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1. Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640 (Japan)
2. Department of Medicine, University of California, San Francisco, CA (United States)
3. Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640 (Japan)

Highlights: • Both the N- and C-termini of IncD are required for the CERT-IncD interaction. • IncD residues essential for the binding to CERT are conserved among Chlamydiaces. • IncD forms multiple oligomers composed of a dimeric unit. Chlamydia trachomatis is an obligate intracellular bacterium that replicates within a membranous compartment, the inclusion, in host cells. Its intracellular life cycle requires host sphingolipids, which are in part acquired through the ER-Golgi localized ceramide transport protein (CERT). The Chlamydia-encoded inclusion membrane protein IncD is composed of two closely linked long hydrophobic domains with their N- and C-termini exposed to the host cytosol. IncD binds directly to the pleckstrin homology (PH) domain of CERT, likely redirecting ceramide to the inclusion. The precise regions of IncD required for this interaction have not been delineated. Using co-transfection studies together with phylogenetic studies, we demonstrate that both the IncD N- and C-terminal regions are required for binding to the CERT PH domain and define key interaction residues. Native gel electrophoresis analysis demonstrates that the transmembrane region of IncD forms SDS-resistant but dithiothreitol-sensitive homodimers, which in turn can assemble to form higher order oligomers through additional N- and C-terminal domain contacts. IncD oligomerization may facilitate high affinity binding to CERT, allowing C. trachomatis to efficiently redirect host ceramide to the inclusion.

• OSTI ID: 23107752
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 4 Vol. 505; ISSN BBRCA9; ISSN 0006-291X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BACTERIA
ELECTROPHORESIS
INCLUSIONS
MEMBRANE PROTEINS