CellStructureMech

paraflagellar rod

GO:0097740 · Appendage · Multiprotein complex · Proposed

A large lattice-like axial structure found in some flagellated protists which extends alongside the axoneme. Protein components of the paraflagellar rod are likely implicated, among other, in adenine nucleotide signaling and metabolism, and in calcium signaling. [GO:0097740]

Synonyms: PFR; paraxial rod

Part of: GO:0097729 — 9+2 motile cilium (no local record)

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

ComponentTypePart of / acts onGroundingGenesStoichiometryEssentialRole
paraflagellar rod protein PFR1Proteinpart ofReviewed label only (reviewed name; no accession asserted)PFR1, PFRC, PFRDESSENTIALMajor lattice protein that co-assembles with PFR2 in the full paraflagellar rod of the studied trypanosome and Leishmania models; Leishmania PFR1 can associate with axoneme attachment fibers without PFR2.
  • PMID:7961827 Deflorin et al. 1994 distinguished the T. brucei 73 kDa PFRC/PFRD product from 69 kDa PFRA/PFRB.
  • DOI:10.1016/j.molbiopara.2004.03.006 Gadelha et al. 2004 consolidate T. brucei PFRC as PFR1, orthologous to Leishmania PFR1.
  • DOI:10.1242/jcs.112.16.2753 Maga et al. 1999 found Leishmania mexicana PFR1 throughout the PFR and required for native formation; PFR1 can associate with attachment fibers without PFR2.
paraflagellar rod protein PFR2Proteinpart ofReviewed label only (reviewed name; no accession asserted)PFR2, PFRA, PFRBCONDITIONALMajor lattice protein required for full native PFR architecture in the studied trypanosome and Leishmania models, not for every reduced PFR. Gadelha et al. found no evidence for PFR2 in the reduced Crithidia deanei rod using several assays, while noting their detection limitations.
  • DOI:10.1083/jcb.109.4.1695 Schlaeppi et al. 1989 characterized the helical PFRA/PFRB product, subsequently assigned to consolidated PFR2.
  • DOI:10.1016/j.molbiopara.2004.03.006 Gadelha et al. 2004 consolidate T. brucei PFRA as PFR2, orthologous to Leishmania PFR2.
  • DOI:10.1242/jcs.112.16.2753 Maga et al. 1999 showed that Leishmania PFR2 is required for native full PFR assembly, while PFR1 can form stable associations with attachment fibers without it.
  • DOI:10.1128/EC.4.3.516-525.2005 Gadelha et al. 2005 imaged a reduced PFR in Crithidia deanei and found no PFR2 with PCR, hybridization and protein assays. The combined negative results support a lineage distinction, not proof of universal gene absence.

Organism-specific protein examples

Named proteins in which each component's role was established, with the organism the evidence comes from. The component above is the taxon-agnostic family; these are the specific entries behind it.

paraflagellar rod protein PFR1

AccessionProteinGeneOrganismEntry
UniProtKB:Q2678973 kDa paraflagellar rod proteinPFRCTrypanosoma brucei brucei (NCBITaxon:5702)REVIEWED
Role and evidence (2 references)

Reviewed UniProtKB entry for the PFRC/PFRD-encoded 73 kDa protein in Trypanosoma brucei brucei, assigned to consolidated PFR1 by Gadelha et al. 2004. The source protein name and historical UniProt mnemonic PFR2_TRYBB are not a cross-species orthology assertion.

  • https://www.uniprot.org/uniprotkb/Q26789 UniProtKB reviewed entry Q26789 verifies the source-native 73 kDa protein name and PFRC/PFRD genes. The consolidated family assignment follows Gadelha et al. 2004, not the ordinal UniProt mnemonic.
  • DOI:10.1016/j.molbiopara.2004.03.006 Table 1 and Fig. 1 map T. brucei PFRC to PFR1 and PFRA to PFR2, consistently with Leishmania nomenclature.

paraflagellar rod protein PFR2

AccessionProteinGeneOrganismEntry
UniProtKB:P2222569 kDa paraflagellar rod proteinPFRATrypanosoma brucei brucei (NCBITaxon:5702)REVIEWED
Role and evidence (2 references)

Reviewed UniProtKB entry for the PFRA/PFRB-encoded 69 kDa protein in Trypanosoma brucei brucei, assigned to consolidated PFR2 by Gadelha et al. 2004. The source protein name and historical UniProt mnemonic PFR1_TRYBB are not a cross-species orthology assertion.

  • https://www.uniprot.org/uniprotkb/P22225 UniProtKB reviewed entry P22225 verifies the source-native 69 kDa protein name and PFRA/PFRB genes. The consolidated family assignment follows Gadelha et al. 2004, not the ordinal UniProt mnemonic.
  • DOI:10.1016/j.molbiopara.2004.03.006 Table 1 and Fig. 1 map T. brucei PFRC to PFR1 and PFRA to PFR2, consistently with Leishmania nomenclature.

Taxonomic distribution

Canonical examples

Functions

Mechanism graphs

PFR1 and PFR2 build the paraflagellar rod lattice (ASSEMBLY)

PFR1 and PFR2 co-assemble into the full PFR lattice in the studied Trypanosoma and Leishmania models. In T. brucei, cytoplasmic PFR-AF1 and PFR-AF2 act upstream of flagellar assembly and support major PFR protein accumulation. This model does not require the same composition in reduced rods such as that of Crithidia deanei.

SubjectPredicateObjectEvidence
paraflagellar rod protein PFR1co-assembles intoparaflagellar rod
paraflagellar rod protein PFR2co-assembles intoparaflagellar rod
paraflagellar rodanchors toaxoneme
  • DOI:10.1242/jcs.112.16.2753 Maga et al. 1999 used Leishmania PFR mutants to show that fibers attaching the PFR to the axoneme can assemble in the absence of the bulk PFR.
PFR assembly factor 1promotes assembly ofparaflagellar rod
  • DOI:10.1242/jcs.242271 Alves et al. 2020 found that deleting PFR-AF1 dramatically disrupts PFR formation in T. brucei.
PFR assembly factor 2promotes assembly ofparaflagellar rod
  • DOI:10.1242/jcs.242271 Alves et al. 2020 found that deleting PFR-AF2 dramatically disrupts PFR formation in T. brucei.

Discussions

Evidence

Curation history

Source: data/structures/appendage/paraflagellar_rod.yaml