PXD044588

PXD044588 is an original dataset announced via ProteomeXchange.

Title	Apical annuli are specialised sites of post-invasion secretion of dense granules in Toxoplasma
Description	Toxoplasma gondii is an intracellular parasite that causes the disease toxoplasmosis in humans. It is a member of the phylum Apicomplexa that also includes significant human pathogens such as Plasmodium spp. and Cryptosporidium spp. causing malaria and diarrheal disease, respectively. These parasites use a programmed sequence of secretory events to find, invade, and then reengineer their host cells to enable parasite growth and proliferation. After invasion, Toxoplasma secretes proteins for host cell remodelling and manipulation from dense granules. The site(s) of dense granule exocytosis, however, has been unknown. In Toxoplasma gondii, small subapical annular structures that are embedded in the inner membrane complex have been observed, but the role or significance of these apical annuli to plasma membrane function has also been unknown. We have identified four integral membrane proteins of the plasma membrane that occur specifically at these apical annular sites. These proteins are an LMBR-domain containing protein TgLMBD3, and three SNARE proteins TgStxPM, TgNPSN, and TgSyp7. Using widefield-microscopy, we discovered that depletion of each of these proteins results in reduced secretion of dense granule proteins, implicating the apical annuli as a site of exocytosis in Toxoplasma. To further understand the role of these proteins and the impact of their depletion on the parasite, we performed whole-cell quantitative proteomics in control and knockdown cell lines. Several hundred proteins have been identified and quantified in three biological replicates for every knockdown cell line and the untreated control line. The majority of enriched proteins in the knockdown cell lines are those packaged in dense granules, indicating their failure to be secreted outside the cell. The apical annuli are therefore sites of SNARE-mediated exocytosis of dense granules in Toxoplasma.
HostingRepository	PRIDE
AnnounceDate	2024-10-22
AnnouncementXML	Submission_2024-10-22_06:25:03.443.xml
DigitalObjectIdentifier	https://dx.doi.org/10.6019/PXD044588
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Supported dataset by repository
PrimarySubmitter	Thomas Krueger
SpeciesList	scientific name: Toxoplasma gondii; NCBI TaxID: 5811;
ModificationList	TMT6plex-126 reporter+balance reagent acylated residue
Instrument	Orbitrap Fusion Lumos

Revision	Datetime	Status	ChangeLog Entry
0	2023-08-15 04:59:58	ID requested
1	2024-01-25 09:16:59	announced
⏵ 2	2024-10-22 06:25:03	announced	2024-10-22: Updated project metadata.

10.6019/PXD044588;

10.7554/ELIFE.94201;

submitter keyword: Toxoplasma, exocytosis, secretion, LMBD, SNARE, apical annuli, dense granules

Ross Waller
contact affiliation	University of Cambridge Department of Biochemistry Hopkins Building Downing Site Tennis Court Road Cambridge CB2 1QW
contact email	rfw26@cam.ac.uk
lab head
Thomas Krueger
contact affiliation	Department of Biochemistry University of Cambridge
contact email	tk556@cam.ac.uk
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD044588
     1. Label: PRIDE project
     2. Name: Apical annuli are specialised sites of post-invasion secretion of dense granules in Toxoplasma