Basic Information | Overview of PTM Sites | Experimental PTM Sites | Protein-Protein Interactions | Drug and Disease Associations | Related Literatures
Basic Information
Protein Name :  Serine/threonine-protein phosphatase 2A activator  

UniProtKB / Swiss-Prot ID :  PTPA_HUMAN

Gene Name (Synonyms) : 
PPP2R4, PTPA  

Species :  Homo sapiens (Human). 

Subcellular Localization :  Cytoplasm. Nucleus. 

Protein Function :  PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. Acts as a regulatory subunit for serine/threonine- protein phosphatase 2A (PP2A) modulating its activity or substrate specificity, probably by inducing a conformational change in the catalytic subunit, a proposed direct target of the PPIase. Can reactivate inactive phosphatase PP2A-phosphatase methylesterase complexes (PP2A(i)) in presence of ATP and Mg(2+) (By similarity). Reversibly stimulates the variable phosphotyrosyl phosphatase activity of PP2A core heterodimer PP2A(D) in presence of ATP and Mg(2+) (in vitro). The phosphotyrosyl phosphatase activity is dependent of an ATPase activty of the PP2A(D):PPP2R4 complex. Is involved in apoptosis; the function appears to be independent from PP2A. 

Protein Sequence MAEGERQPPPDSSEEAPPATQNFIIPKKEIHTVPDMGKWKRSQAYADYIGFILTLNEGVKGKKLTFEYRV...
Predicted Secondary Structure CCCCCCCCCCCCCCCCCCCCCEEECCEEEECCHHHHHHHHCCCHHHHHHHHHHHHHHHCCCCCCCCCCCC...
Protein Variant
LocationDescription
28K -> R (in dbSNP:rs17481693). VAR_028101
208R -> Q (in dbSNP:rs4836639). VAR_028102
357S -> L (in dbSNP:rs2480452). VAR_028103
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Overview of Protein Modification Sites with Functional and Structural Information
Accessible Surface Area (ASA)
Pred. Secondary
Real Secondary
Disorder Prediction
Protein Domain
&
Experimental PTM Sites
Predicted PTM Sites
Protein Variant
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Experimental Post-Translational Modification Sites Download
Locations
Modification
Substrate Sites
&
Secondary Structure
Accessible Surface Area (%)
Resource
Reference
Structural Characterization
Orthologous
Protein Cluster
2N-acetylalanine.---MAEGER
---CCCCCC
33.24UniProtKB
Link-
27Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)FIIPKKEIH
EECCEEEEC
53.26Phosphositeplus
Link
62N6-acetyllysineGVKGKKLTF
HCCCCCCCC
38.60HPRD
Link
62N6-acetyllysineGVKGKKLTF
HCCCCCCCC
38.60Phosphositeplus
Link
62N6-acetyllysine.GVKGKKLTF
HCCCCCCCC
38.60UniProtKB
Link
111N6-acetyllysineEAIEKLVAL
HHHHHHHHH
41.99HPRD
Link
126PhosphothreonineWIDETPPVD
HHHHCCCCC
29.19HPRD
Link
223PhosphotyrosineVFNRYLEVM
HHHHHHHHH
14.33Phosphositeplus
Link
277Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)FVDEKAVNE
CCCCHHHHH
53.85Phosphositeplus
Link
331N6-acetyllysineIRMYKAECL
HHHHHHHHH
28.50HPRD
Link-
331N6-acetyllysineIRMYKAECL
HHHHHHHHH
28.50Phosphositeplus
Link-
337N6-acetyllysineECLEKFPVI
HHHCCCCEE
41.86HPRD
Link-
337N6-acetyllysineECLEKFPVI
HHHCCCCEE
41.86Phosphositeplus
Link-
337N6-acetyllysine.ECLEKFPVI
HHHCCCCEE
41.86UniProtKB
Link-
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Protein-Protein Interactions
      Interacting Protein      
Interaction type
Source ID
      Resource      
      Pubmed ID      
Domain-Domain Interactions
CSK21_HUMANin vitro
in vivo
HPRD:02858HPRD9139659
CDC6_HUMANENSP00000337448STRING
PPR1B_HUMANENSP00000337448STRING
AXN1_HUMANENSP00000337448STRING
TAU_HUMANENSP00000337448STRING
OPSD_HUMANENSP00000337448STRING
CCNG2_HUMANENSP00000337448STRING
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Disease Reference
Kegg disease
There are no disease associations of PTM sites.
Drug Reference
There are no disease associations of PTM sites.
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Related Literatures of Post-Translational Modification
Acetylation
ReferencePubMed
"Lys-N and trypsin cover complementary parts of the phosphoproteome ina refined SCX-based approach.";
Gauci S., Helbig A.O., Slijper M., Krijgsveld J., Heck A.J.,Mohammed S.;
Anal. Chem. 81:4493-4501(2009).
Cited for: ACETYLATION [LARGE SCALE ANALYSIS] AT ALA-2, AND MASS SPECTROMETRY.
"Lysine acetylation targets protein complexes and co-regulates majorcellular functions.";
Choudhary C., Kumar C., Gnad F., Nielsen M.L., Rehman M., Walther T.,Olsen J.V., Mann M.;
Science 325:834-840(2009).
Cited for: ACETYLATION [LARGE SCALE ANALYSIS] AT LYS-62 AND LYS-337, AND MASSSPECTROMETRY.
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Basic Information | Overview of PTM Sites | Experimental PTM Sites | Protein-Protein Interactions | Drug and Disease Associations | Related Literatures