PXD055593-1

PXD055593 is an original dataset announced via ProteomeXchange.

Title	Unwrapping the ciliary coat: high-resolution structure and function of the ciliary glycocalyx in Chlamydomonas
Description	The outermost layer of eukaryotic cilia is a coat of membrane anchored, glycosylated proteins often referred to as glycocalyx. This highly heterogeneous layer provides functions from regulation of adhesion, force transduction and protection to signaling. We describe the structure of the ciliary coat of the green alga Chlamydomonas by cryo-electron tomography and proteomic approaches and present the high-resolution single particle structure of FMG1B via cryo-electron microscopy, the most abundant constituent of the ciliary coat. We report FMG1B to be a highly unusual mucin orthologue, which lacks the major O-glycosylation of mammalian mucins, but undergoes significant N-glycosylation. We find that an isoform of FMG1-B, FMG1-A, previously believed to be not expressed, is present in Chlamydomonas and differentially regulated with FMG1-B. By micro-flow-based adhesion assays, we observe increased surface adhesion in the glycocalyx deficient double-mutant fmg1a-fmg1b. We find this mutant to be fully capable of surface-gliding, suggesting that neither isoform is required for extracellular force transduction by intraflagellar transport. Our data provide in-depth structural details of the ciliary coat that functions as the primary contact to the environment and reveal that FMG1 acts primarily as a protective layer with adhesion-regulative properties. Data deposited here include label free quantification data on whole cells or isolated cilia confirming single knockout of FMG1B and high abundance of FMG1A in CC4533fmg1b (combined_protein_WC_CC4533fmg1b.tsv ) and double knockout of FMG1A and FMG1B in M32fmg1afmg1b (combined_proteinCilia_M32_M32fmg1afmg1b.tsv). The latter dataset was further analyzed for abundance changes in the cilia proteome (Log2_LFQ_ratios_M32_M32fmg1afmg1b.csv). Further, isolated cilia of wild type M32 were analyzed under non-reducing conditions to confirm structure predicted disulfide bridges via LC-MS/MS in FMG1B (FMG1B_intraprotein_disulfides.xlsx). Finally, isolated cilia of M32 were subjected to N-glycopeptide analyses using InSource-CID (FMG1B_HexNAc_modified_peptides.xlsx).
HostingRepository	PRIDE
AnnounceDate	2025-04-29
AnnouncementXML	Submission_2025-04-29_01:09:31.883.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Lara Melanie Hoepfner
SpeciesList	scientific name: Chlamydomonas reinhardtii; NCBI TaxID: 3055;
ModificationList	No PTMs are included in the dataset
Instrument	Q Exactive HF

Revision	Datetime	Status	ChangeLog Entry
0	2024-09-05 10:47:13	ID requested
⏵ 1	2025-04-29 01:09:32	announced

10.1002/ADVS.202413355;

submitter keyword: Cilia, Adhesion, Glycocalyx, N-glycosylation,Chlamydomonas, Disulfides

Michael Hippler
contact affiliation	Institute of Plant Biology and Biotechnology, University of Münster, Germany
contact email	mhippler@uni-muenster.de
lab head
Lara Melanie Hoepfner
contact affiliation	IBBP-Plant Biochemistry and Biotechnology AG Prof. Dr. Michael Hippler University of Münster
contact email	l_hoep03@wwu.de
dataset submitter

Dataset FTP location NOTE: Most web browsers have now discontinued native support for FTP access within the browser window. But you can usually install another FTP app (we recommend FileZilla) and configure your browser to launch the external application when you click on this FTP link. Or otherwise, launch an app that supports FTP (like FileZilla) and use this address: ftp://ftp.pride.ebi.ac.uk/pride/data/archive/2025/04/PXD055593

PRIDE project URI

• PRIDE
  1. PXD055593
     1. Label: PRIDE project
     2. Name: Unwrapping the ciliary coat: high-resolution structure and function of the ciliary glycocalyx in Chlamydomonas