ATG2/YNL242W Summary Help

Standard Name ATG2 1
Systematic Name YNL242W
Alias SPO72 2 , AUT8 3 , APG2 4
Feature Type ORF, Verified
Description Peripheral membrane protein required for autophagic vesicle formation; also required for vesicle formation during pexophagy and the cytoplasm-to-vaucole targeting (Cvt) pathway; involved in Atg9p cycling between the phagophore assembly site and mitochondria; essential for cell cycle progression from G2/M to G1 under nitrogen starvation; forms cytoplasmic foci upon DNA replication stress (4, 5, 6, 7, 8 and see Summary Paragraph)
Name Description AuTophaGy related 1
Chromosomal Location
ChrXIV:191324 to 196102 | ORF Map | GBrowse
Gbrowse
Gene Ontology Annotations All ATG2 GO evidence and references
  View Computational GO annotations for ATG2
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
High-throughput
Regulators 13 genes
Resources
Classical genetics
null
reduction of function
Large-scale survey
null
Resources
32 total interaction(s) for 18 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 11
  • Affinity Capture-RNA: 2
  • Affinity Capture-Western: 4
  • Co-localization: 2
  • Two-hybrid: 3

Genetic Interactions
  • Negative Genetic: 9
  • Phenotypic Suppression: 1

Resources
Expression Summary
histogram
Resources
Length (a.a.) 1,592
Molecular Weight (Da) 178,412
Isoelectric Point (pI) 5.78
Localization
Phosphorylation PhosphoGRID | PhosphoPep Database
Structure
Homologs
sequence information
ChrXIV:191324 to 196102 | ORF Map | GBrowse
SGD ORF map
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Relative
Coordinates
Chromosomal
Coordinates
Most Recent Updates
Coordinates Sequence
CDS 1..4779 191324..196102 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
Resources
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000005186
SUMMARY PARAGRAPH for ATG2

about autophagy...

Autophagy is a highly conserved eukaryotic pathway for sequestering and transporting bulk cytoplasm, including proteins and organelle material, to the lysosome for degradation (reviewed in 9). Upon starvation for nutrients such as carbon, nitrogen, sulfur, and various amino acids, or upon endoplasmic reticulum stress, cells initiate formation of a double-membrane vesicle, termed an autophagosome, that mediates this process (10, 11, reviewed in 12). Approximately 30 autophagy-related (Atg) proteins have been identified in S. cerevisiae, 17 of which are essential for formation of the autophagosome (reviewed in 13). Null mutations in most of these genes prevent induction of autophagy, and cells do not survive nutrient starvation; however, these mutants are viable in rich medium. Some of the Atg proteins are also involved in a constitutive biosynthetic process termed the cytoplasm-to-vacuole targeting (Cvt) pathway, which uses autophagosomal-like vesicles for selective transport of hydrolases aminopeptidase I (Lap4p) and alpha-mannosidase (Ams1p) to the vacuole (3, 14).

Autophagy proceeds via a multistep pathway (a summary diagram (download pdf) kindly provided by Dan Klionsky). First, nutrient availability is sensed by the TORC1 complex and also cooperatively by protein kinase A and Sch9p (15, 16). Second, signals generated by the sensors are transmitted to the autophagosome-generating machinery comprised of the 17 Atg gene products. These 17 proteins collectively form the pre-autophagosomal structure/phagophore assembly site (PAS). The PAS generates an isolation membrane (IM), which expands and eventually fuses along the edges to complete autophagosome formation. At the vacuole the outer membrane of the autophagosome fuses with the vacuolar membrane and autophagic bodies are released, disintegrated, and their contents degraded for reuse in biosynthesis (17 and reviewed in 13).

about the Cytoplasm-to-vacuole targeting (Cvt) pathway

Cytoplasm-to-vacuole targeting (Cvt) is a constitutive and specific form of autophagy that uses autophagosomal-like vesicles for selective transport of hydrolases aminopeptidase I (Lap4p) and alpha-mannosidase (Ams1p) to the vacuole (3, 14). Unlike autophagy, which is primarily a catabolic process, Cvt is a biosynthetic process. Like autophagosomes, Cvt vesicles form at a structure known as the phagophore assembly site (PAS) (also called the pre-autophagosomal structure). The PAS structure generates an isolation membrane (IM), which expands and eventually fuses along the edges to complete vesicle formation. At the vacuole, the outer membrane of the Cvt vesicle fuses with the vacuolar membrane, the vesicle is degraded, and the cargos are released and processed into their mature forms by vacuolar peptidases (reviewed in 18). The Cvt pathway has not been observed outside of yeast, and enzymes specifically involved in this pathway are not well conserved in other organisms (19 and references therein).

about ATG2

ATG2 encodes a protein that is required for vesicle nucleation/formation during autophagy and the Cvt pathway (20, 5). Atg2p localizes to the PAS and is involved in cycling of the integral membrane protein Atg9p from the PAS to the mitochondria (17, 6, and reviewed in 21). Atg2p and Atg18p have been shown to work together as a complex to facilitate proper Atg9p cycling (22). Localization of Atg2p is dependent on Atg9p, Atg1p, the PtdIns 3-kinase complex I (comprised of Vps34p, Vps15p, Vps30p, and Atg14p), and Atg18p (20, 22). atg2 mutants are defective in autophagy, Cvt transport, sporulation, pexophagy, and survival under starvation conditions (5, 2). ATG2 is highly conserved, and homologs have been identified in organisms such as other yeasts, Arabidopsis, and humans (19).

about autophagy nomenclature

The initial identification of factors involved in autophagy was carried out by several independent labs, which led to a proliferation of nomenclature for the genes and gene products involved. The differing gene name acronyms from these groups included APG, AUT, CVT, GSA, PAG, PAZ, and PDD (1 and references therein). A concerted effort was made in 2003 by the scientists working in the field to unify the nomenclature for these genes, and "AuTophaGy-related" genes are now denoted by the letters ATG (1). In addition to the ATG gene names that have been assigned to S. cerevisiae proteins and their orthologs, several ATG gene names, including ATG25, ATG28, and ATG30, have been used to designate proteins in other ascomycete yeast species for which there is no identifiable equivalent in S. cerevisiae (19, 23).

Last updated: 2008-02-08 Contact SGD

References cited on this page View Complete Literature Guide for ATG2
1) Klionsky DJ, et al.  (2003) A unified nomenclature for yeast autophagy-related genes. Dev Cell 5(4):539-45
2) Barth H and Thumm M  (2001) A genomic screen identifies AUT8 as a novel gene essential for autophagy in the yeast Saccharomyces cerevisiae. Gene 274(1-2):151-6
3) Harding TM, et al.  (1996) Genetic and phenotypic overlap between autophagy and the cytoplasm to vacuole protein targeting pathway. J Biol Chem 271(30):17621-4
4) Tsukada M and Ohsumi Y  (1993) Isolation and characterization of autophagy-defective mutants of Saccharomyces cerevisiae. FEBS Lett 333(1-2):169-74
5) Wang CW, et al.  (2001) Apg2 is a novel protein required for the cytoplasm to vacuole targeting, autophagy, and pexophagy pathways. J Biol Chem 276(32):30442-51
6) Reggiori F, et al.  (2004) The Atg1-Atg13 complex regulates Atg9 and Atg23 retrieval transport from the pre-autophagosomal structure. Dev Cell 6(1):79-90
7) Tkach JM, et al.  (2012) Dissecting DNA damage response pathways by analysing protein localization and abundance changes during DNA replication stress. Nat Cell Biol 14(9):966-76
8) Matsui A, et al.  (2013) The role of autophagy in genome stability through suppression of abnormal mitosis under starvation. PLoS Genet 9(1):e1003245
9) Budovskaya YV, et al.  (2004) The Ras/cAMP-dependent protein kinase signaling pathway regulates an early step of the autophagy process in Saccharomyces cerevisiae. J Biol Chem 279(20):20663-71
10) Takeshige K, et al.  (1992) Autophagy in yeast demonstrated with proteinase-deficient mutants and conditions for its induction. J Cell Biol 119(2):301-11
11) Matsuura A, et al.  (1997) Apg1p, a novel protein kinase required for the autophagic process in Saccharomyces cerevisiae. Gene 192(2):245-50
12) Yorimitsu T and Klionsky DJ  (2007) Endoplasmic reticulum stress: a new pathway to induce autophagy. Autophagy 3(2):160-2
13) Suzuki K and Ohsumi Y  (2007) Molecular machinery of autophagosome formation in yeast, Saccharomyces cerevisiae. FEBS Lett 581(11):2156-61
14) Yorimitsu T and Klionsky DJ  (2005) Atg11 links cargo to the vesicle-forming machinery in the cytoplasm to vacuole targeting pathway. Mol Biol Cell 16(4):1593-605
15) Yorimitsu T, et al.  (2007) Protein Kinase A and Sch9 Cooperatively Regulate Induction of Autophagy in Saccharomyces cerevisiae. Mol Biol Cell 18(10):4180-9
16) Noda T and Ohsumi Y  (1998) Tor, a phosphatidylinositol kinase homologue, controls autophagy in yeast. J Biol Chem 273(7):3963-6
17) Suzuki K, et al.  (2001) The pre-autophagosomal structure organized by concerted functions of APG genes is essential for autophagosome formation. EMBO J 20(21):5971-81
18) Kim J and Klionsky DJ  (2000) Autophagy, cytoplasm-to-vacuole targeting pathway, and pexophagy in yeast and mammalian cells. Annu Rev Biochem 69:303-42
19) Meijer WH, et al.  (2007) ATG genes involved in non-selective autophagy are conserved from yeast to man, but the selective Cvt and pexophagy pathways also require organism-specific genes. Autophagy 3(2):106-16
20) Shintani T, et al.  (2001) Apg2p functions in autophagosome formation on the perivacuolar structure. J Biol Chem 276(32):30452-60
21) Yorimitsu T and Klionsky DJ  (2005) Autophagy: molecular machinery for self-eating. Cell Death Differ 12 Suppl 2():1542-52
22) Suzuki K, et al.  (2007) Hierarchy of Atg proteins in pre-autophagosomal structure organization. Genes Cells 12(2):209-18
23) Farre JC, et al.  (2008) PpAtg30 tags peroxisomes for turnover by selective autophagy. Dev Cell 14(3):365-76