PXD074423

PXD074423 is an original dataset announced via ProteomeXchange.

Title	QIQ1-dependent bicarbonate-sensing in trypanosomes
Description	Cells sense and adapt to their environment. Parasitic protists for example, such as African trypanosomes, occupy distinct environments in mammalian hosts, and in insect vectors, and adapt energy metabolism and growth accordingly, but the mechanisms involved remain incompletely characterized. Here we describe environmental sensing dependent upon Trypanosoma brucei Quick IQ-motif protein 1 (QIQ1). We use a genome-scale loss-of-function genetic screen to identify knockdowns associated with gain-of-fitness, or a ‘quick’ growth phenotype, in bloodstream-form cells. The dominant hit, QIQ1 (Tb927.8.6870), encodes a flagellum-localized protein with multiple putative calmodulin-binding IQ-motifs. In a competition assay, qiq1-null cells displayed a density-dependent growth advantage, which was abrogated by calcium chelation. When cells were grown at reduced density in blood serum, with a series of supplements, only bicarbonate restored the qiq1-null competitive advantage. Proteomic analysis indicated that QIQ1 increased the expression of carnitine acetyltransferase, suggesting a role in modulating fatty acid metabolism, while expression of a flagellum-localized calmodulin was both QIQ1 and bicarbonate-dependent. We conclude that trypanosomes sense and adapt to distinct environments in a QIQ1-dependent manner. Our findings suggest that QIQ1-signaling facilitates CO2-sensing to optimize utilization of available nutrients via a pathway involving calcium, calmodulin, and carnitine.
HostingRepository	PRIDE
AnnounceDate	2026-02-13
AnnouncementXML	Submission_2026-02-13_04:16:17.524.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Michele Tinti
SpeciesList	scientific name: Trypanosoma brucei; NCBI TaxID: NEWT:5691;
ModificationList	carbamoylated residue
Instrument	Orbitrap Exploris 480

Revision	Datetime	Status	ChangeLog Entry
0	2026-02-13 03:24:43	ID requested
⏵ 1	2026-02-13 04:16:19	announced

Dataset with its publication pending

submitter keyword: trypanosomes QIQ1

David Horn
contact affiliation	Chair of Parasite Molecular Biology Biological Chemistry and Drug Discovery, School of Life Sciences
contact email	d.horn@dundee.ac.uk
lab head
Michele Tinti
contact affiliation	Dundee University
contact email	m.tinti@dundee.ac.uk
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD074423
     1. Label: PRIDE project
     2. Name: QIQ1-dependent bicarbonate-sensing in trypanosomes