5W3S

Cryo-electron microscopy structure of a TRPML3 ion channel


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.94 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Cryo-electron microscopy structure of the lysosomal calcium-permeable channel TRPML3.

Hirschi, M.Herzik, M.A.Wie, J.Suo, Y.Borschel, W.F.Ren, D.Lander, G.C.Lee, S.Y.

(2017) Nature 550: 411-414

  • DOI: 10.1038/nature24055

  • PubMed Abstract: 
  • The modulation of ion channel activity by lipids is increasingly recognized as a fundamental component of cellular signalling. The transient receptor potential mucolipin (TRPML) channel family belongs to the TRP superfamily and is composed of three m ...

    The modulation of ion channel activity by lipids is increasingly recognized as a fundamental component of cellular signalling. The transient receptor potential mucolipin (TRPML) channel family belongs to the TRP superfamily and is composed of three members: TRPML1-TRPML3. TRPMLs are the major Ca 2+ -permeable channels on late endosomes and lysosomes (LEL). They regulate the release of Ca 2+ from organelles, which is important for various physiological processes, including organelle trafficking and fusion. Loss-of-function mutations in the MCOLN1 gene, which encodes TRPML1, cause the neurodegenerative lysosomal storage disorder mucolipidosis type IV, and a gain-of-function mutation (Ala419Pro) in TRPML3 gives rise to the varitint-waddler (Va) mouse phenotype. Notably, TRPML channels are activated by the low-abundance and LEL-enriched signalling lipid phosphatidylinositol-3,5-bisphosphate (PtdIns(3,5)P 2 ), whereas other phosphoinositides such as PtdIns(4,5)P 2 , which is enriched in plasma membranes, inhibit TRPMLs. Conserved basic residues at the N terminus of the channel are important for activation by PtdIns(3,5)P 2 and inhibition by PtdIns(4,5)P 2 . However, owing to a lack of structural information, the mechanism by which TRPML channels recognize PtdIns(3,5)P 2 and increase their Ca 2+ conductance remains unclear. Here we present the cryo-electron microscopy (cryo-EM) structure of a full-length TRPML3 channel from the common marmoset (Callithrix jacchus) at an overall resolution of 2.9 Å. Our structure reveals not only the molecular basis of ion conduction but also the unique architecture of TRPMLs, wherein the voltage sensor-like domain is linked to the pore via a cytosolic domain that we term the mucolipin domain. Combined with functional studies, these data suggest that the mucolipin domain is responsible for PtdIns(3,5)P 2 binding and subsequent channel activation, and that it acts as a 'gating pulley' for lipid-dependent TRPML gating.


    Organizational Affiliation

    Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA.,Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, USA.,Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Mucolipin-3 isoform 1
A, B, C, D
561Callithrix jacchusMutation(s): 1 
Gene Names: MCOLN3
Membrane protein
mpstruc
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Transient Receptor Potential (TRP)
Protein: 
TRPML3 ion channel
Find proteins for F6RG56 (Callithrix jacchus)
Go to Gene View: MCOLN3
Go to UniProtKB:  F6RG56
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
Y01
Query on Y01

Download SDF File 
Download CCD File 
A, B, C, D
CHOLESTEROL HEMISUCCINATE
C31 H50 O4
WLNARFZDISHUGS-MIXBDBMTSA-N
 Ligand Interaction
NA
Query on NA

Download SDF File 
Download CCD File 
A, C, D
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
3PE
Query on 3PE

Download SDF File 
Download CCD File 
A, B, C, D
1,2-DIACYL-SN-GLYCERO-3-PHOSPHOETHANOLAMINE
3-SN-PHOSPHATIDYLETHANOLAMINE
C41 H82 N O8 P
LVNGJLRDBYCPGB-LDLOPFEMSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.94 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
Software Package:
Software NamePurpose
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of Neurological Disorders and StrokeUnited StatesR35NS097241
National Institutes of Health/National Institute of Biomedical Imaging and BioengineeringUnited StatesDP2EB020402

Revision History 

  • Version 1.0: 2017-10-11
    Type: Initial release
  • Version 1.1: 2017-10-25
    Type: Database references
  • Version 1.2: 2017-11-01
    Type: Database references