W0THY6 · ATG8_KLUMD

Function

function

Ubiquitin-like modifier involved in cytoplasm to vacuole transport (Cvt) vesicles and autophagosome formation (PubMed:26442587).
With ATG4, mediates the delivery of the vesicles and autophagosomes to the vacuole via the microtubule cytoskeleton (By similarity).
Required for selective autophagic degradation of the nucleus (nucleophagy) as well as for mitophagy which contributes to regulate mitochondrial quantity and quality by eliminating the mitochondria to a basal level to fulfill cellular energy requirements and preventing excess ROS production (By similarity).
Participates also in membrane fusion events that take place in the early secretory pathway (By similarity).
Also involved in endoplasmic reticulum-specific autophagic process and is essential for the survival of cells subjected to severe ER stress (By similarity).
The ATG8-PE conjugate mediates tethering between adjacent membranes and stimulates membrane hemifusion, leading to expansion of the autophagosomal membrane during autophagy (By similarity).
Moreover not only conjugation, but also subsequent ATG8-PE deconjugation is an important step required to facilitate multiple events during macroautophagy, and especially for efficient autophagosome biogenesis, the assembly of ATG9-containing tubulovesicular clusters into phagophores/autophagosomes, and for the disassembly of PAS-associated ATG components (By similarity).

Miscellaneous

Kluyveromyces marxianus proteins are shorter in length and have a more ordered secondary structure than their S.cerevisiae counterparts, which might contribute to the superior thermotolerance and solubility (PubMed:26442587).
K.marxianus could be therefore useful as a new model organism for further elucidation of the molecular details of autophagy (PubMed:26442587).

Features

Showing features for site.

TypeIDPosition(s)Description
Site116-117Cleavage; by ATG4

GO annotations

AspectTerm
Cellular Componentautophagosome membrane
Cellular ComponentCvt vesicle membrane
Cellular Componentcytosol
Cellular Componentfungal-type vacuole membrane
Molecular Functionphosphatidylethanolamine binding
Biological Processcellular response to nitrogen starvation
Biological Processmacroautophagy
Biological Processprotein transport

Keywords

Names & Taxonomy

Protein names

  • Recommended name
    Autophagy-related protein 8
  • Alternative names
    • Autophagy-related ubiquitin-like modifier ATG8

Gene names

    • Name
      ATG8
    • ORF names
      KLMA_80372

Organism names

Accessions

  • Primary accession
    W0THY6

Proteomes

Organism-specific databases

Subcellular Location

Cytoplasmic vesicle, cvt vesicle membrane
; Lipid-anchor
Cytoplasmic vesicle, autophagosome membrane
; Lipid-anchor
Vacuole membrane
; Lipid-anchor
Note: Membrane-associated through a lipid anchor (By similarity).
This association needs the 2 ubiquitin-like systems required for cytoplasm to vacuole transport and autophagy (By similarity).
Localizes to both the isolation membrane (IM) and the vacuole-isolation membrane contact site (VICS) during IM expansion (By similarity).
The IM is a membrane sac generated from the pre-autophagosomal structure that ultimately expands to become a mature autophagosome (By similarity).
Accumulates atperivacuolar sites under high temperature conditions (PubMed:26442587).

Keywords

Phenotypes & Variants

Disruption phenotype

Blocks autophagic activity by impairing the formation of autophagic bodies (PubMed:26442587).

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis116In Atg8FA; prevents conjugation with phosphatidylethanolamine (PE) and impairs the correct localization to autophagic membranes.
Mutagenesis117-124In Atg8FG; bypasses the requirement for cleavage by ATG4 to be localized to autophagic membranes.

PTM/Processing

Features

Showing features for chain, lipidation, propeptide.

TypeIDPosition(s)Description
ChainPRO_00004438911-124
Lipidation116Phosphatidylethanolamine amidated glycine
PropeptidePRO_0000443892117-124Removed in mature form

Post-translational modification

The C-terminal 8 residues of ATG8 are removed by ATG4 to expose Gly-116 at the C-terminus (By similarity).
This Gly-116 forms then a thioester bond with the 'Cys-550' of ATG7 (E1-like activating enzyme) before being transferred to the 'Cys-244' of ATG3 (the specific E2 conjugating enzyme), in order to be finally amidated with phosphatidylethanolamine (By similarity).
This lipid modification anchors ATG8 to membranes and can be reversed by ATG4, releasing soluble ATG8 (By similarity).

Keywords

Interaction

Subunit

Conjugation to phosphatidylethanolamine (PE) leads to homodimerization (By similarity).
Interacts with ATG1, ATG3, ATG4, ATG7 and ATG12 (By similarity).

Structure

Family & Domains

Sequence similarities

Belongs to the ATG8 family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.
  • Length
    124
  • Mass (Da)
    14,137
  • Last updated
    2014-03-19 v1
  • Checksum
    2E5BAF8E7A9464A3
MKSAFKSEFPFEKRKAESERIVQKFHNRIPVICERGGKSDIPDIDKRKYLVPGDLTVGQFVYVIRKRIKLPAEKAIFIFVNDTLPPTAALMSSIYQHHKDKDGFLYVSYSSENTFGGAGPLLEK

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AP012220
EMBL· GenBank· DDBJ
BAO42683.1
EMBL· GenBank· DDBJ
Genomic DNA

Similar Proteins

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