Comparative GO Graph (mouse, human, rat, zebrafish)

• Source: Alliance of Genome Resources

Graphs for Molecular Function, Cellular Component, Biological Process generated Fri Mar 10 16:36:22 2023.

Complete table of the annotations represented in this image is provided below.

Graphs display curated GO classifications for mouse, human, rat and zebrafish orthologs annotated from the biomedical literature.

• This class contains
  • Human genes PER2
  • Mouse genes Per2
  • Rat genes Per2
  • Zfish genes per2
• Annotations are indicated with nodes colored by organism: Human, Mouse, Rat, Zfish
• Relations between GO terms are indicated by colored edges "is_a"; "part_of"; "regulates"; "positively_regulates"; "negatively_regulates"
• GO annotations: Human from GOA; Mouse from MGI; Rat from RGD; Zebrafish from ZFIN.
• Only experimental annotations are displayed: EXP, IDA, IEP, IGI, IMP, IPI, HTP, HDA, HMP, HGI, HEP. Evidence codes are listed at the bottom of the page.

Molecular Function

Cellular Component

Biological Process

Full set of experimental annotations for Human-Rat-Zebrafish genes considered orthologs of Mouse in the Alliance stringent orthology set Per2

Category	ID	Classification term	Gene	Evidence	Inferred from	Organism	Reference
Molecular Function	GO:0003682	chromatin binding	per2	IDA		Zfish	PMID:25673850
Molecular Function	GO:0140297	DNA-binding transcription factor binding	Per2	IPI	UniProtKB:P97784|UniProtKB:Q9WTL8	Mouse	MGI:MGI:4429726|PMID:20159955
Molecular Function	GO:0140297	DNA-binding transcription factor binding	Per2	IPI	UniProtKB:O08785|UniProtKB:Q9WTL8	Mouse	MGI:MGI:5567903|PMID:21613214
Molecular Function	GO:0042826	histone deacetylase binding	Per2	IPI	UniProtKB:O09106	Mouse	MGI:MGI:5569417|PMID:24413057
Molecular Function	GO:1990226	histone methyltransferase binding	Per2	IPI	UniProtKB:O54864|UniProtKB:Q9EQQ0	Mouse	MGI:MGI:5569417|PMID:24413057
Molecular Function	GO:0042802	identical protein binding	Per2	IPI	UniProtKB:O54943	Mouse	MGI:MGI:3850870|PMID:19402751
Molecular Function	GO:0042802	identical protein binding	Per2	IPI	UniProtKB:O54943	Mouse	MGI:MGI:4455093|PMID:20211142
Molecular Function	GO:0042802	identical protein binding	Per2	IPI	UniProtKB:O54943	Mouse	MGI:MGI:5568139|PMID:24737000
Molecular Function	GO:0019900	kinase binding	Per2	IPI	UniProtKB:Q9JMK2	Mouse	MGI:MGI:3027197|PMID:14701732
Molecular Function	GO:0019900	kinase binding	Per2	IPI	UniProtKB:Q9JMK2	Mouse	MGI:MGI:5014424|PMID:21680841
Molecular Function	GO:0019900	kinase binding	Per2	IPI	UniProtKB:Q9JMK2	Mouse	MGI:MGI:5569417|PMID:24413057
Molecular Function	GO:0016922	nuclear receptor binding	Per2	IPI	UniProtKB:P23204|UniProtKB:P49698|UniProtKB:P63058|UniProtKB:Q06219|UniProtKB:Q3UV55	Mouse	MGI:MGI:4429726|PMID:20159955
Molecular Function	GO:0016922	nuclear receptor binding	Per2	IPI	UniProtKB:P37238	Mouse	MGI:MGI:4881351|PMID:21035761
Molecular Function	GO:0016922	nuclear receptor binding	Per2	IPI	UniProtKB:P20393	Mouse	MGI:MGI:5302136|PMID:22170608
Molecular Function	GO:0036002	pre-mRNA binding	Per2	IDA		Mouse	MGI:MGI:5430667|PMID:22767893
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P49674	Human	PMID:16790549
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P49674	Human	PMID:17218255
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P48730	Human	PMID:21179498
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P29590	Human	PMID:22274616
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P49674	Human	PMID:28514442
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P41235	Human	PMID:30530698
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:J3QSH9	Human	PMID:32296183
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P11441	Human	PMID:32296183
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P40692	Human	PMID:32296183
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P48730	Human	PMID:32296183
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P49674	Human	PMID:32296183
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:P61968	Human	PMID:32296183
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:Q14241	Human	PMID:32296183
Molecular Function	GO:0005515	protein binding	PER2	IPI	UniProtKB:Q96PV6	Human	PMID:32296183
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:P97784|UniProtKB:Q9JMK2	Mouse	MGI:MGI:5569417|PMID:24413057
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O08785|UniProtKB:Q9WTL8	Mouse	MGI:MGI:3694308|PMID:16717091
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q9R194	Mouse	MGI:MGI:5294528|PMID:20840750
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:P97784|UniProtKB:Q8C4V4	Mouse	MGI:MGI:5470183|PMID:23452855
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q60953	Mouse	MGI:MGI:5314433|PMID:22274616
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O08785|UniProtKB:Q923E4	Mouse	MGI:MGI:3807721|PMID:18662546
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O08785	Mouse	MGI:MGI:3807721|PMID:18662546
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O08785|UniProtKB:Q9WTL8	Mouse	MGI:MGI:4881368|PMID:20832105
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q9JMK2	Mouse	MGI:MGI:4946906|PMID:21179498
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q8C4V4	Mouse	MGI:MGI:5487698|PMID:23452856
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q3TQ03	Mouse	MGI:MGI:5545849|PMID:24385426
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q9DC28|UniProtKB:Q9JMK2	Mouse	MGI:MGI:3849793|PMID:19414593
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O70361|UniProtKB:P97784|UniProtKB:Q9R194	Mouse	MGI:MGI:3027197|PMID:14701732
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q8VIJ6|UniProtKB:Q99K48	Mouse	MGI:MGI:5444785|PMID:22966205
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:P97784|UniProtKB:Q16526	Mouse	MGI:MGI:5567903|PMID:21613214
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O08785	Mouse	MGI:MGI:5489023|PMID:23555304
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O35973|UniProtKB:P20393|UniProtKB:P97784|UniProtKB:Q8N365|UniProtKB:Q9R194	Mouse	MGI:MGI:5568139|PMID:24737000
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:P97784|UniProtKB:Q9JMK2|UniProtKB:Q9R194	Mouse	MGI:MGI:5489023|PMID:23555304
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q3TQ03	Mouse	MGI:MGI:5568140|PMID:24736997
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q2VPD4|UniProtKB:Q9WTL8	Mouse	MGI:MGI:4410413|PMID:19605937
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q9R1X4	Mouse	MGI:MGI:1316573|PMID:9856465
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q9CQV6	Mouse	MGI:MGI:6208175|PMID:29937374
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:P23198|UniProtKB:P97784	Mouse	MGI:MGI:5569417|PMID:24413057
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O08785|UniProtKB:O35973|UniProtKB:Q16526|UniProtKB:Q60520|UniProtKB:Q8VIJ6|UniProtKB:Q9WTL8	Mouse	MGI:MGI:5014424|PMID:21680841
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:P97784	Mouse	MGI:MGI:5572897|PMID:11889036
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:P97784|UniProtKB:Q9R194	Mouse	MGI:MGI:5302136|PMID:22170608
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O35973	Mouse	MGI:MGI:4455093|PMID:20211142
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:P97784	Mouse	MGI:MGI:5578016|PMID:23418588
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O08785|UniProtKB:Q9WTL8	Mouse	MGI:MGI:3829113|PMID:18430226
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:O35973|UniProtKB:P97784|UniProtKB:Q91VJ2|UniProtKB:Q9JMK2|UniProtKB:Q9R194	Mouse	MGI:MGI:5508702|PMID:23079727
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q9R194	Mouse	MGI:MGI:5508675|PMID:23503662
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q9WTL8	Mouse	MGI:MGI:3652692|PMID:16777965
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:P97784	Mouse	MGI:MGI:5586772|PMID:24855952
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q9QZ04	Mouse	MGI:MGI:5607219|PMID:22208286
Molecular Function	GO:0005515	protein binding	Per2	IPI	PR:Q3UYV9	Mouse	PMID:22767893
Molecular Function	GO:0005515	protein binding	Per2	IPI	PR:O70133	Mouse	PMID:22767893
Molecular Function	GO:0005515	protein binding	Per2	IPI	PR:O70361	Mouse	PMID:9856466
Molecular Function	GO:0005515	protein binding	Per2	IPI	PR:A2AKX3	Mouse	PMID:22767893
Molecular Function	GO:0005515	protein binding	Per2	IPI	PR:Q61656	Mouse	PMID:22767893
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q9Z2Y1	Rat	PMID:11112428|RGD:2308863
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q3ULA2	Rat	PMID:18782782|RGD:8554786
Molecular Function	GO:0005515	protein binding	Per2	IPI	UniProtKB:Q5SRY7	Rat	PMID:18782782|RGD:8554786
Molecular Function	GO:0005515	protein binding	Per2	IPI	RGD:620939	Rat	PMID:9765215|RGD:61691
Molecular Function	GO:0070063	RNA polymerase binding	Per2	IPI	UniProtKB:P08775	Mouse	MGI:MGI:5430667|PMID:22767893
Molecular Function	GO:0000978	RNA polymerase II cis-regulatory region sequence-specific DNA binding	Per2	IDA		Mouse	MGI:MGI:5292598|PMID:21768648
Molecular Function	GO:0000976	transcription cis-regulatory region binding	Per2	IDA		Mouse	MGI:MGI:5014424|PMID:21680841
Molecular Function	GO:0000976	transcription cis-regulatory region binding	Per2	IDA		Mouse	MGI:MGI:5569417|PMID:24413057
Molecular Function	GO:0003713	transcription coactivator activity	Per2	IDA		Mouse	MGI:MGI:4429726|PMID:20159955
Molecular Function	GO:0001222	transcription corepressor binding	Per2	IPI	UniProtKB:Q62318	Mouse	MGI:MGI:5569417|PMID:24413057
Cellular Component	GO:0005737	cytoplasm	Per2	IDA		Mouse	MGI:MGI:5572897|PMID:11889036
Cellular Component	GO:0005737	cytoplasm	Per2	IDA		Mouse	MGI:MGI:5607219|PMID:22208286
Cellular Component	GO:0005737	cytoplasm	Per2	IDA		Mouse	PMID:15689618
Cellular Component	GO:0005829	cytosol	PER2	IDA		Human	GO_REF:0000052
Cellular Component	GO:0005654	nucleoplasm	PER2	IDA		Human	GO_REF:0000052
Cellular Component	GO:0005634	nucleus	PER2	IDA		Human	PMID:22274616
Cellular Component	GO:0005634	nucleus	Per2	IDA		Mouse	MGI:MGI:5578016|PMID:23418588
Cellular Component	GO:0005634	nucleus	Per2	IDA		Mouse	MGI:MGI:5314433|PMID:22274616
Cellular Component	GO:0005634	nucleus	Per2	IDA		Mouse	MGI:MGI:5607219|PMID:22208286
Cellular Component	GO:0005634	nucleus	Per2	IDA		Mouse	MGI:MGI:5567916|PMID:15860628
Cellular Component	GO:0005634	nucleus	Per2	IDA		Mouse	MGI:MGI:5572897|PMID:11889036
Cellular Component	GO:0005634	nucleus	Per2	IPI	PR:Q9R194	Mouse	PMID:15689618
Cellular Component	GO:0005634	nucleus	Per2	IDA		Mouse	PMID:22767893
Cellular Component	GO:0005634	nucleus	Per2	IDA		Rat	PMID:11533252|RGD:69505
Cellular Component	GO:0048471	perinuclear region of cytoplasm	Per2	IDA		Mouse	MGI:MGI:5314433|PMID:22274616
Biological Process	GO:0006338	chromatin remodeling	Per2	IMP		Mouse	MGI:MGI:5014424|PMID:21680841
Biological Process	GO:0032922	circadian regulation of gene expression	Per2	IDA		Mouse	MGI:MGI:4429726|PMID:20159955
Biological Process	GO:0032922	circadian regulation of gene expression	Per2	IMP		Mouse	MGI:MGI:4410390|PMID:19917250
Biological Process	GO:0032922	circadian regulation of gene expression	Per2	IMP		Mouse	MGI:MGI:1935010|PMID:11395012
Biological Process	GO:0032922	circadian regulation of gene expression	Per2	IMP		Mouse	MGI:MGI:5319572|PMID:22504074
Biological Process	GO:0032922	circadian regulation of gene expression	per2	IMP	ZFIN:ZDB-GENO-150417-7	Zfish	PMID:29593513
Biological Process	GO:0097167	circadian regulation of translation	Per2	IMP		Mouse	MGI:MGI:1935010|PMID:11395012
Biological Process	GO:0007623	circadian rhythm	Per2	IEP		Mouse	MGI:MGI:4420353|PMID:19740747
Biological Process	GO:0007623	circadian rhythm	Per2	IEP		Mouse	MGI:MGI:5559671|PMID:14645221
Biological Process	GO:0007623	circadian rhythm	Per2	IEP		Mouse	MGI:MGI:5503234|PMID:23785138
Biological Process	GO:0007623	circadian rhythm	Per2	IEP		Mouse	MGI:MGI:3838062|PMID:19217292
Biological Process	GO:0007623	circadian rhythm	Per2	IDA		Mouse	PMID:12843397
Biological Process	GO:0007623	circadian rhythm	Per2	IEP		Rat	PMID:15094047|RGD:8554359
Biological Process	GO:0007623	circadian rhythm	Per2	IEP		Rat	PMID:9765215|RGD:61691
Biological Process	GO:0007623	circadian rhythm	Per2	IEP		Rat	PMID:9878515|RGD:10043346
Biological Process	GO:0043153	entrainment of circadian clock by photoperiod	per2	IMP	ZFIN:ZDB-MRPHLNO-050708-2	Zfish	PMID:15869567
Biological Process	GO:0043153	entrainment of circadian clock by photoperiod	per2	IMP	ZFIN:ZDB-MRPHLNO-050708-2	Zfish	PMID:16537499
Biological Process	GO:0043153	entrainment of circadian clock by photoperiod	per2	IMP	ZFIN:ZDB-MRPHLNO-060407-1	Zfish	PMID:16537499
Biological Process	GO:0006631	fatty acid metabolic process	Per2	IMP		Mouse	MGI:MGI:5546525|PMID:23977055
Biological Process	GO:0006094	gluconeogenesis	Per2	IMP		Mouse	MGI:MGI:5319572|PMID:22504074
Biological Process	GO:0005978	glycogen biosynthetic process	Per2	IMP	UniProtKB:Q3UV55	Mouse	MGI:MGI:4429726|PMID:20159955
Biological Process	GO:0019249	lactate biosynthetic process	Per2	IMP		Mouse	MGI:MGI:5546525|PMID:23977055
Biological Process	GO:0045475	locomotor rhythm	per2	IMP	ZFIN:ZDB-MRPHLNO-060407-1	Zfish	PMID:24423866
Biological Process	GO:0016525	negative regulation of angiogenesis	per2	IMP	ZFIN:ZDB-MRPHLNO-050708-2	Zfish	PMID:22884368
Biological Process	GO:0042754	negative regulation of circadian rhythm	Per2	IDA		Mouse	MGI:MGI:4410413|PMID:19605937
Biological Process	GO:0045892	negative regulation of DNA-templated transcription	Per2	IDA		Mouse	MGI:MGI:5607219|PMID:22208286
Biological Process	GO:0045892	negative regulation of DNA-templated transcription	Per2	IDA		Mouse	MGI:MGI:5532917|PMID:17310242
Biological Process	GO:0045892	negative regulation of DNA-templated transcription	Per2	IDA		Mouse	MGI:MGI:4410413|PMID:19605937
Biological Process	GO:0045892	negative regulation of DNA-templated transcription	Per2	IDA		Mouse	MGI:MGI:5292598|PMID:21768648
Biological Process	GO:0045892	negative regulation of DNA-templated transcription	Per2	IDA		Mouse	MGI:MGI:5553247|PMID:12738229
Biological Process	GO:0045892	negative regulation of DNA-templated transcription	Per2	IDA		Rat	PMID:12397359|RGD:625726
Biological Process	GO:0070345	negative regulation of fat cell proliferation	Per2	IMP		Mouse	MGI:MGI:4881351|PMID:21035761
Biological Process	GO:0031397	negative regulation of protein ubiquitination	Per2	IDA		Mouse	MGI:MGI:5572897|PMID:11889036
Biological Process	GO:0060567	negative regulation of termination of DNA-templated transcription	Per2	IDA		Mouse	MGI:MGI:5430667|PMID:22767893
Biological Process	GO:0000122	negative regulation of transcription by RNA polymerase II	Per2	IMP		Mouse	MGI:MGI:4881351|PMID:21035761
Biological Process	GO:0000122	negative regulation of transcription by RNA polymerase II	Per2	IDA		Mouse	PMID:9989497
Biological Process	GO:0000122	negative regulation of transcription by RNA polymerase II	Per2	IDA		Rat	PMID:12397359|RGD:625726
Biological Process	GO:0000122	negative regulation of transcription by RNA polymerase II	Per2	IDA		Rat	PMID:14672706|RGD:8554012
Biological Process	GO:0000122	negative regulation of transcription by RNA polymerase II	Per2	IDA		Rat	PMID:15147242|RGD:8554138
Biological Process	GO:2000678	negative regulation of transcription regulatory region DNA binding	Per2	IMP		Mouse	MGI:MGI:4881351|PMID:21035761
Biological Process	GO:0009648	photoperiodism	per2	IEP		Zfish	PMID:11517315
Biological Process	GO:0042753	positive regulation of circadian rhythm	per2	IMP	ZFIN:ZDB-GENO-150417-7	Zfish	PMID:25544291
Biological Process	GO:0120162	positive regulation of cold-induced thermogenesis	Per2	IMP		Mouse	MGI:MGI:5638508|PMID:24049733
Biological Process	GO:0051726	regulation of cell cycle	Per2	IMP		Mouse	MGI:MGI:5553036|PMID:24268780
Biological Process	GO:0042752	regulation of circadian rhythm	Per2	IMP		Mouse	MGI:MGI:1935010|PMID:11395012
Biological Process	GO:0042752	regulation of circadian rhythm	Per2	IMP		Mouse	MGI:MGI:4410390|PMID:19917250
Biological Process	GO:0051946	regulation of glutamate uptake involved in transmission of nerve impulse	Per2	IMP		Mouse	MGI:MGI:3687603|PMID:16595674
Biological Process	GO:0050796	regulation of insulin secretion	Per2	IMP		Mouse	MGI:MGI:5319572|PMID:22504074
Biological Process	GO:0050767	regulation of neurogenesis	Per2	IMP		Mouse	MGI:MGI:5553036|PMID:24268780
Biological Process	GO:0019229	regulation of vasoconstriction	Per2	IMP		Mouse	MGI:MGI:3794791|PMID:17404161
Biological Process	GO:0009409	response to cold	per2	IDA		Zfish	PMID:27846817
Biological Process	GO:0042542	response to hydrogen peroxide	per2	IEP		Zfish	PMID:17898172
Biological Process	GO:0002931	response to ischemia	Per2	IMP		Mouse	MGI:MGI:5546525|PMID:23977055
Biological Process	GO:0009416	response to light stimulus	per2	IDA		Zfish	PMID:16176122
Biological Process	GO:0009416	response to light stimulus	per2	IDA		Zfish	PMID:18800057
Biological Process	GO:0009416	response to light stimulus	per2	IMP	ZFIN:ZDB-GENO-150417-7	Zfish	PMID:29593513
Biological Process	GO:0009416	response to light stimulus	per2	IDA		Zfish	PMID:16000406
Biological Process	GO:0009416	response to light stimulus	per2	IEP		Zfish	PMID:15869567
Biological Process	GO:0009416	response to light stimulus	per2	IDA		Zfish	PMID:16537499
Biological Process	GO:0009416	response to light stimulus	per2	IDA		Zfish	PMID:17785416
Biological Process	GO:0009416	response to light stimulus	per2	IDA		Zfish	PMID:14986634
Biological Process	GO:0009411	response to UV	per2	IDA		Zfish	PMID:7565671
Biological Process	GO:0050872	white fat cell differentiation	Per2	IMP		Mouse	MGI:MGI:4881351|PMID:21035761

Gene Ontology Evidence Code Abbreviations:

  EXP Inferred from experiment

  IDA Inferred from direct assay

  IEP Inferred from expression pattern

  IGI Inferred from genetic interaction

  IMP Inferred from mutant phenotype

  IPI Inferred from physical interaction

  HTP Inferred from High Throughput Experiment

  HDA Inferred from High Throughput Direct Assay

  HMP Inferred from High Throughput Mutant Phenotype

  HGI Inferred from High Throughput Genetic Interaction

  HEP Inferred from High Throughput Expression Pattern