Q09137 (AAPK2_RAT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
5'-AMP-activated protein kinase catalytic subunit alpha-2
Short name=AMPK subunit alpha-2
EC=2.7.11.1

Gene names

Name:	Prkaa2
Synonyms:	Ampk, Ampk2

Organism

Rattus norvegicus (Rat)

Taxonomic identifier

10116 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Glires › Rodentia › Sciurognathi › Muroidea › Muridae › Murinae › Rattus

Protein attributes

Sequence length	552 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Catalytic subunit of AMP-activated protein kinase (AMPK), an energy sensor protein kinase that plays a key role in regulating cellular energy metabolism. In response to reduction of intracellular ATP levels, AMPK activates energy-producing pathways and inhibits energy-consuming processes: inhibits protein, carbohydrate and lipid biosynthesis, as well as cell growth and proliferation. AMPK acts via direct phosphorylation of metabolic enzymes, and by longer-term effects via phosphorylation of transcription regulators. Also acts as a regulator of cellular polarity by remodeling the actin cytoskeleton; probably by indirectly activating myosin. Regulates lipid synthesis by phosphorylating and inactivating lipid metabolic enzymes such as ACACA, ACACB, GYS1, HMGCR and LIPE; regulates fatty acid and cholesterol synthesis by phosphorylating acetyl-CoA carboxylase (ACACA and ACACB) and hormone-sensitive lipase (LIPE) enzymes, respectively. Regulates insulin-signaling and glycolysis by phosphorylating IRS1, PFKFB2 and PFKFB3. AMPK stimulates glucose uptake in muscle by increasing the translocation of the glucose transporter SLC2A4/GLUT4 to the plasma membrane, possibly by mediating phosphorylation of TBC1D4/AS160. Regulates transcription and chromatin structure by phosphorylating transcription regulators involved in energy metabolism such as CRTC2/TORC2, FOXO3, histone H2B, HDAC5, MEF2C, MLXIPL/ChREBP, EP300, HNF4A, p53/TP53, SREBF1, SREBF2 and PPARGC1A. Acts as a key regulator of glucose homeostasis in liver by phosphorylating CRTC2/TORC2, leading to CRTC2/TORC2 sequestration in the cytoplasm. In response to stress, phosphorylates 'Ser-36' of histone H2B (H2BS36ph), leading to promote transcription. Acts as a key regulator of cell growth and proliferation by phosphorylating TSC2, RPTOR and ATG1: in response to nutrient limitation, negatively regulates the mTORC1 complex by phosphorylating RPTOR component of the mTORC1 complex and by phosphorylating and activating TSC2. In response to nutrient limitation, promotes autophagy by phosphorylating and activating ULK1. AMPK also acts as a regulator of circadian rhythm by mediating phosphorylation of CRY1, leading to destabilize it. May regulate the Wnt signaling pathway by phosphorylating CTNNB1, leading to stabilize it. Also phosphorylates CFTR, EEF2K, KLC1, NOS3 and SLC12A1. Ref.3 Ref.5 Ref.6 Ref.7 Ref.8 Ref.9 Ref.10 Ref.12 Ref.13 Ref.15 Ref.18
Catalytic activity	ATP + a protein = ADP + a phosphoprotein.
Cofactor	Magnesium By similarity.
Enzyme regulation	Activated by phosphorylation on Thr-172. Binding of AMP to non-catalytic gamma subunit (PRKAG1, PRKAG2 or PRKAG3) results in allosteric activation, inducing phosphorylation on Thr-172. AMP-binding to gamma subunit also sustains activity by preventing dephosphorylation of Thr-172. ADP also stimulates Thr-172 phosphorylation, without stimulating already phosphorylated AMPK. ATP promotes dephosphorylation of Thr-172, rendering the enzyme inactive. Under physiological conditions AMPK mainly exists in its inactive form in complex with ATP, which is much more abundant than AMP. Selectively inhibited by compound C (6-[4-(2-Piperidin-1-yl-ethoxy)-phenyl)]-3-pyridin-4-yl-pyyrazolo[1,5-a] pyrimidine. Activated by resveratrol, a natural polyphenol present in red wine, and S17834, a synthetic polyphenol. Ref.4 Ref.11 Ref.12 Ref.16 Ref.17
Subunit structure	AMPK is a heterotrimer of an alpha catalytic subunit (PRKAA1 or PRKAA2), a beta (PRKAB1 or PRKAB2) and a gamma non-catalytic subunits (PRKAG1, PRKAG2 or PRKAG3). Interacts with FNIP1 and FNIP2.
Subcellular location	Cytoplasm By similarity. Nucleus By similarity. Note: In response to stress, recruited by p53/TP53 to specific promoters By similarity.
Tissue specificity	Skeletal muscle, lower levels in liver, heart and kidney.
Induction	By AMP. Ref.4 Ref.11 Ref.12 Ref.16 Ref.17
Domain	The AIS (autoinhibitory sequence) region some sequence similarity with the ubiquitin-associated domains and represses kinase activity By similarity.
Post-translational modification	Ubiquitinated By similarity. Phosphorylated at Thr-172 by STK11/LKB1 in complex with STE20-related adapter-alpha (STRADA) pseudo kinase and CAB39. Also phosphorylated at Thr-172 by CAMKK2; triggered by a rise in intracellular calcium ions, without detectable changes in the AMP/ATP ratio. CAMKK1 can also phosphorylate Thr-172, but at much lower lvel. Dephosphorylated by protein phosphatase 2A and 2C (PP2A and PP2C). Phosphorylated by ULK1; leading to negatively regulate AMPK activity and suggesting the existence of a regulatory feedback loop between ULK1 and AMPK. Ref.3 Ref.4 Ref.5 Ref.6 Ref.7 Ref.8 Ref.9 Ref.10 Ref.11 Ref.12 Ref.13 Ref.14 Ref.15 Ref.16 Ref.17 Ref.18 Ref.19
Sequence similarities	Belongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family. SNF1 subfamily. Contains 1 protein kinase domain.

Ontologies

Keywords
Biological process	Autophagy Biological rhythms Cholesterol biosynthesis Fatty acid biosynthesis Lipid synthesis Steroid biosynthesis Sterol biosynthesis Transcription Transcription regulation Wnt signaling pathway
Cellular component	Cytoplasm Nucleus
Coding sequence diversity	Alternative splicing
Ligand	ATP-binding Magnesium Metal-binding Nucleotide-binding
Molecular function	Chromatin regulator Kinase Serine/threonine-protein kinase Transferase
PTM	Acetylation Phosphoprotein Ubl conjugation
Technical term	Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological process	Wnt receptor signaling pathway Inferred from electronic annotation. Source: UniProtKB-KW autophagy Inferred from electronic annotation. Source: UniProtKB-KW cellular response to glucose starvation Inferred from sequence or structural similarity. Source: UniProtKB cellular response to organic nitrogen Inferred from expression pattern. Source: RGD cholesterol biosynthetic process Inferred from electronic annotation. Source: UniProtKB-KW fatty acid biosynthetic process Inferred from electronic annotation. Source: UniProtKB-KW fatty acid homeostasis Inferred from direct assay Ref.9. Source: UniProtKB glucose homeostasis Inferred from sequence or structural similarity. Source: UniProtKB negative regulation of TOR signaling cascade Inferred from sequence or structural similarity. Source: UniProtKB negative regulation of apoptotic process Inferred from sequence or structural similarity. Source: UniProtKB positive regulation of autophagy Inferred from sequence or structural similarity. Source: UniProtKB positive regulation of glycolysis Inferred from direct assay Ref.7. Source: UniProtKB protein heterooligomerization Inferred from direct assay Ref.12. Source: RGD regulation of circadian rhythm Inferred from sequence or structural similarity. Source: UniProtKB regulation of energy homeostasis Inferred from direct assay Ref.9. Source: UniProtKB regulation of lipid metabolic process Inferred from direct assay. Source: RGD regulation of transcription, DNA-dependent Inferred from electronic annotation. Source: UniProtKB-KW response to activity Inferred from direct assay. Source: RGD response to caffeine Inferred from direct assay. Source: RGD rhythmic process Inferred from electronic annotation. Source: UniProtKB-KW transcription, DNA-dependent Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	AMP-activated protein kinase complex Inferred from direct assay. Source: RGD apical plasma membrane Inferred from direct assay. Source: UniProtKB cytoplasm Inferred from direct assay. Source: UniProtKB nucleoplasm Traceable author statement. Source: Reactome
Molecular function	AMP-activated protein kinase activity Inferred from direct assay Ref.7Ref.9. Source: UniProtKB ATP binding Inferred from direct assay. Source: RGD chromatin binding Inferred from sequence or structural similarity. Source: UniProtKB histone serine kinase activity Inferred from sequence or structural similarity. Source: UniProtKB metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW protein binding, bridging Inferred from direct assay. Source: RGD
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]

Isoform Long (identifier: Q09137-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Isoform Short (identifier: Q09137-2)

The sequence of this isoform differs from the canonical sequence as follows:
     32-388: Missing.
     392-552: Missing.

Note: Lacks the sequence parts essential for kinase activity and is therefore inactive.

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 552	552	5'-AMP-activated protein kinase catalytic subunit alpha-2		PRO_0000085597
Regions
	Domain	16 – 268	253	Protein kinase
	Nucleotide binding	22 – 30	9	ATP By similarity
	Region	291 – 376	86	AIS By similarity
Sites
	Active site	139	1	Proton acceptor By similarity
	Binding site	45	1	ATP By similarity
Amino acid modifications
	Modified residue	69	1	N6-acetyllysine By similarity
	Modified residue	172	1	Phosphothreonine; by LKB1 and CaMKK2 Ref.4 Ref.11 Ref.12 Ref.16 Ref.17
	Modified residue	173	1	Phosphoserine By similarity
	Modified residue	176	1	Phosphoserine By similarity
	Modified residue	258	1	Phosphothreonine Ref.14
	Modified residue	377	1	Phosphoserine By similarity
	Modified residue	491	1	Phosphoserine Ref.14
	Modified residue	500	1	Phosphoserine By similarity
Natural variations
	Alternative sequence	32 – 388	357	Missing in isoform Short.		VSP_004949
	Alternative sequence	392 – 552	161	Missing in isoform Short.		VSP_004950
Experimental info
	Sequence conflict	355	1	M → S in AAA85033. Ref.2
	Sequence conflict	462	1	N → D in AAA85033. Ref.2

Sequences

	Sequence		Length	Mass (Da)
	Isoform Long [UniParc]. Last modified February 1, 1995. Version 1. Checksum: 2829E07F674D89B1	FASTA	552	62,258
	10 20 30 40 50 60 MAEKQKHDGR VKIGHYVLGD TLGVGTFGKV KIGEHQLTGH KVAVKILNRQ KIRSLDVVGK 70 80 90 100 110 120 IKREIQNLKL FRHPHIIKLY QVISTPTDFF MVMEYVSGGE LFDYICKHGR VEEVEARRLF 130 140 150 160 170 180 QQILSAVDYC HRHMVVHRDL KPENVLLDAQ MNAKIADFGL SNMMSDGEFL RTSCGSPNYA 190 200 210 220 230 240 APEVISGRLY AGPEVDIWSC GVILYALLCG TLPFDDEHVP TLFKKIRGGV FYIPEYLNRS 250 260 270 280 290 300 IATLLMHMLQ VDPLKRATIK DIREHEWFKQ DLPSYLFPED PSYDANVIDD EAVKEVCEKF 310 320 330 340 350 360 ECTESEVMNS LYSGDPQDQL AVAYHLIIDN RRIMNQASEF YLASSPPTGS FMDDMAMHIP 370 380 390 400 410 420 PGLKPHPERM PPLIADSPKA RCPLDALNTT KPKSLAVKKA KWHLGIRSQS KPYDIMAEVY 430 440 450 460 470 480 RAMKQLDFEW KVVNAYHLRV RRKNPVTGNY VKMSLQLYLV DNRSYLLDFK SIDDEVVEQR 490 500 510 520 530 540 SGSSTPQRSC SAAGLHRPRS SVDSSTAENH SLSGSLTGSL TGSTLSSASP RLGSHTMDFF 550 EMCASLITAL AR
	Isoform Short [UniParc]. Checksum: 4BF6E5CF5CF23F3B	FASTA	34	3,700
	10 20 30 MAEKQKHDGR VKIGHYVLGD TLGVGTFGKV KTTK

References

[1]	"Mammalian AMP-activated protein kinase is homologous to yeast and plant protein kinases involved in the regulation of carbon metabolism." Carling D., Aguan K., Woods A., Verhoeven A.J.M., Beri R.K., Brennan C.H., Sidebottom C., Davison M.D., Scott J. J. Biol. Chem. 269:11442-11448(1994) [PubMed: 7908907] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORMS LONG AND SHORT), PARTIAL PROTEIN SEQUENCE. Tissue: Liver.
[2]	"Catalytic subunits of the porcine and rat 5'-AMP-activated protein kinase are members of the SNF1 protein kinase family." Gao G., Widmer J., Stapleton D., Teh T., Cox T., Kemp B.E., Witters L.A. Biochim. Biophys. Acta 1266:73-82(1995) [PubMed: 7718624] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM LONG). Strain: Sprague-Dawley. Tissue: Liver.
[3]	"Regulation of HMG-CoA reductase: identification of the site phosphorylated by the AMP-activated protein kinase in vitro and in intact rat liver." Clarke P.R., Hardie D.G. EMBO J. 9:2439-2446(1990) [PubMed: 2369897] [Abstract] Cited for: FUNCTION IN PHOSPHORYLATION OF HMGCR.
[4]	"Characterization of the AMP-activated protein kinase kinase from rat liver and identification of threonine 172 as the major site at which it phosphorylates AMP-activated protein kinase." Hawley S.A., Davison M., Woods A., Davies S.P., Beri R.K., Carling D., Hardie D.G. J. Biol. Chem. 271:27879-27887(1996) [PubMed: 8910387] [Abstract] Cited for: PHOSPHORYLATION AT THR-172, ENZYME REGULATION.
[5]	"Phosphorylation of rat muscle acetyl-CoA carboxylase by AMP-activated protein kinase and protein kinase A." Winder W.W., Wilson H.A., Hardie D.G., Rasmussen B.B., Hutber C.A., Call G.B., Clayton R.D., Conley L.M., Yoon S., Zhou B. J. Appl. Physiol. 82:219-225(1997) [PubMed: 9029219] [Abstract] Cited for: FUNCTION IN PHOSPHORYLATION OF ACACA AND ACACB.
[6]	"AMP-activated protein kinase phosphorylation of endothelial NO synthase." Chen Z.P., Mitchelhill K.I., Michell B.J., Stapleton D., Rodriguez-Crespo I., Witters L.A., Power D.A., Ortiz de Montellano P.R., Kemp B.E. FEBS Lett. 443:285-289(1999) [PubMed: 10025949] [Abstract] Cited for: FUNCTION IN PHOSPHORYLATION OF NOS3.
[7]	"Phosphorylation and activation of heart PFK-2 by AMPK has a role in the stimulation of glycolysis during ischaemia." Marsin A.S., Bertrand L., Rider M.H., Deprez J., Beauloye C., Vincent M.F., Van den Berghe G., Carling D., Hue L. Curr. Biol. 10:1247-1255(2000) [PubMed: 11069105] [Abstract] Cited for: FUNCTION IN PHOSPHORYLATION OF PFKFB2.
[8]	"5'-AMP-activated protein kinase phosphorylates IRS-1 on Ser-789 in mouse C2C12 myotubes in response to 5-aminoimidazole-4-carboxamide riboside." Jakobsen S.N., Hardie D.G., Morrice N., Tornqvist H.E. J. Biol. Chem. 276:46912-46916(2001) [PubMed: 11598104] [Abstract] Cited for: FUNCTION IN PHOSPHORYLATION OF IRS1.
[9]	"Mechanism for fatty acid 'sparing' effect on glucose-induced transcription: regulation of carbohydrate-responsive element-binding protein by AMP-activated protein kinase." Kawaguchi T., Osatomi K., Yamashita H., Kabashima T., Uyeda K. J. Biol. Chem. 277:3829-3835(2002) [PubMed: 11724780] [Abstract] Cited for: FUNCTION IN PHOSPHORYLATION OF MLXIPL.
[10]	"The stimulation of glycolysis by hypoxia in activated monocytes is mediated by AMP-activated protein kinase and inducible 6-phosphofructo-2-kinase." Marsin A.S., Bouzin C., Bertrand L., Hue L. J. Biol. Chem. 277:30778-30783(2002) [PubMed: 12065600] [Abstract] Cited for: FUNCTION IN PHOSPHORYLATION OF PFKFB3.
[11]	"LKB1 is the upstream kinase in the AMP-activated protein kinase cascade." Woods A., Johnstone S.R., Dickerson K., Leiper F.C., Fryer L.G., Neumann D., Schlattner U., Wallimann T., Carlson M., Carling D. Curr. Biol. 13:2004-2008(2003) [PubMed: 14614828] [Abstract] Cited for: PHOSPHORYLATION AT THR-172, ENZYME REGULATION.
[12]	"Complexes between the LKB1 tumor suppressor, STRAD alpha/beta and MO25 alpha/beta are upstream kinases in the AMP-activated protein kinase cascade." Hawley S.A., Boudeau J., Reid J.L., Mustard K.J., Udd L., Makela T.P., Alessi D.R., Hardie D.G. J. Biol. 2:28.1-28.16(2003) [PubMed: 14511394] [Abstract] Cited for: FUNCTION, ENZYME REGULATION, PHOSPHORYLATION AT THR-172.
[13]	"AMP-activated protein kinase regulates HNF4alpha transcriptional activity by inhibiting dimer formation and decreasing protein stability." Hong Y.H., Varanasi U.S., Yang W., Leff T. J. Biol. Chem. 278:27495-27501(2003) [PubMed: 12740371] [Abstract] Cited for: FUNCTION IN PHOSPHORYLATION OF HNF4A.
[14]	"Identification of phosphorylation sites in AMP-activated protein kinase (AMPK) for upstream AMPK kinases and study of their roles by site-directed mutagenesis." Woods A., Vertommen D., Neumann D., Turk R., Bayliss J., Schlattner U., Wallimann T., Carling D., Rider M.H. J. Biol. Chem. 278:28434-28442(2003) [PubMed: 12764152] [Abstract] Cited for: PHOSPHORYLATION AT THR-258 AND SER-491, MASS SPECTROMETRY.
[15]	"Stimulation of the AMP-activated protein kinase leads to activation of eukaryotic elongation factor 2 kinase and to its phosphorylation at a novel site, serine 398." Browne G.J., Finn S.G., Proud C.G. J. Biol. Chem. 279:12220-12231(2004) [PubMed: 14709557] [Abstract] Cited for: FUNCTION IN PHOSPHORYLATION OF EEF2K.
[16]	"Calmodulin-dependent protein kinase kinase-beta is an alternative upstream kinase for AMP-activated protein kinase." Hawley S.A., Pan D.A., Mustard K.J., Ross L., Bain J., Edelman A.M., Frenguelli B.G., Hardie D.G. Cell Metab. 2:9-19(2005) [PubMed: 16054095] [Abstract] Cited for: PHOSPHORYLATION AT THR-172, ENZYME REGULATION.
[17]	"Ca2+/calmodulin-dependent protein kinase kinase-beta acts upstream of AMP-activated protein kinase in mammalian cells." Woods A., Dickerson K., Heath R., Hong S.-P., Momcilovic M., Johnstone S.R., Carlson M., Carling D. Cell Metab. 2:21-33(2005) [PubMed: 16054096] [Abstract] Cited for: PHOSPHORYLATION AT THR-172, ENZYME REGULATION.
[18]	"Regulation of the renal-specific Na+-K+-2Cl- co-transporter NKCC2 by AMP-activated protein kinase (AMPK)." Fraser S.A., Gimenez I., Cook N., Jennings I., Katerelos M., Katsis F., Levidiotis V., Kemp B.E., Power D.A. Biochem. J. 405:85-93(2007) [PubMed: 17341212] [Abstract] Cited for: FUNCTION IN PHOSPHORYLATION OF SLC12A1.
[19]	"Ulk1-mediated phosphorylation of AMPK constitutes a negative regulatory feedback loop." Loffler A.S., Alers S., Dieterle A.M., Keppeler H., Franz-Wachtel M., Kundu M., Campbell D.G., Wesselborg S., Alessi D.R., Stork B. Autophagy 7:696-706(2011) [PubMed: 21460634] [Abstract] Cited for: PHOSPHORYLATION BY ULK1.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	Z29486 mRNA. Translation: CAA82620.1. U12149 mRNA. Translation: AAA85033.1.
IPI	IPI00201424. IPI00231190.
PIR	A53621.
RefSeq	NP_076481.1. NM_023991.1.
UniGene	Rn.64583.
3D structure databases
ProteinModelPortal	Q09137.
SMR	Q09137. Positions 10-278, 402-485.
ModBase	Search...
Protein-protein interaction databases
STRING	Q09137.
PTM databases
PhosphoSite	Q09137.
Proteomic databases
PRIDE	Q09137.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	78975.
KEGG	rno:78975.
UCSC	NM_023991. rat.
Organism-specific databases
CTD	5563.
RGD	620893. Prkaa2.
Phylogenomic databases
eggNOG	roNOG12508.
GeneTree	ENSGT00600000084026.
HOVERGEN	HBG050432.
InParanoid	Q09137.
OrthoDB	EOG4XSKPM.
PhylomeDB	Q09137.
Enzyme and pathway databases
BRENDA	2.7.11.1. 5301.
Reactome	REACT_113568. Metabolism.
Gene expression databases
ArrayExpress	Q09137.
Genevestigator	Q09137.
GermOnline	ENSRNOG00000007706. Rattus norvegicus.
Family and domain databases
InterPro	IPR011009. Kinase-like_dom. IPR000719. Prot_kinase_cat_dom. IPR017441. Protein_kinase_ATP_BS. IPR017442. Se/Thr_kinase-like_dom. IPR008271. Ser/Thr_kinase_AS. IPR002290. Ser/Thr_kinase_dom. [Graphical view]
KO	K07198.
Pfam	PF00069. Pkinase. 1 hit. [Graphical view]
SMART	SM00220. S_TKc. 1 hit. [Graphical view]
SUPFAM	SSF56112. Kinase_like. 1 hit.
PROSITE	PS00107. PROTEIN_KINASE_ATP. 1 hit. PS50011. PROTEIN_KINASE_DOM. 1 hit. PS00108. PROTEIN_KINASE_ST. 1 hit. [Graphical view]
ProtoNet	Search...
Other
NextBio	614450.

Entry information

Entry name

AAPK2_RAT

Accession

Primary (citable) accession number: Q09137

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 1, 1995
Last sequence update:	February 1, 1995
Last modified:	December 14, 2011
This is version 107 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program