Seroatlas · Human Serome Atlas

HYKK

Hydroxylysine kinase

Also known as: AGPHD1, HYKK_HUMAN, LOC123688

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession: A2RU49
Gene: HYKK
Ensembl: ENSG00000188266
Chromosome: 15
Canonical length: 373 aa
Protein class: Enzymes, Metabolic proteins, Predicted intracellular proteins
Subcellular location: Nucleoplasm,Vesicles,Aggresome,Cytosol

OverviewNCBI Gene

Enables hydroxylysine kinase activity. Predicted to be involved in lysine catabolic process. Predicted to be located in mitochondrial matrix. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

373 residues, UniProt reviewed canonical sequence.

>A2RU49|HYKK
     1  MSSGNYQQSE ALSKPTFSEE QASALVESVF GLKVSKVRPL PSYDDQNFHV YVSKTKDGPT
    61  EYVLKISNTK ASKNPDLIEV QNHIIMFLKA AGFPTASVCH TKGDNTASLV SVDSGSEIKS
   121  YLVRLLTYLP GRPIAELPVS PQLLYEIGKL AAKLDKTLQR FHHPKLSSLH RENFIWNLKN
   181  VPLLEKYLYA LGQNRNREIV EHVIHLFKEE VMTKLSHFRE CINHGDLNDH NILIESSKSA
   241  SGNAEYQVSG ILDFGDMSYG YYVFEVAITI MYMMIESKSP IQVGGHVLAG FESITPLTAV
   301  EKGALFLLVC SRFCQSLVMA AYSCQLYPEN KDYLMVTAKT GWKHLQQMFD MGQKAVEEIW
   361  FETAKSYESG ISM

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against HYKK can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability: Intracellular
Secreted: No
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.24
Highest tissue expression: 12 nTPM

Expression across tissuesHPA

Tissue

kidney: 12 nTPM
choroid plexus: 8.2 nTPM
duodenum: 6.8 nTPM
small intestine: 6.8 nTPM
pancreas: 6.5 nTPM
skeletal muscle: 5.9 nTPM

Single-cell type

myosatellite cells: 69 nCPM
late spermatids: 52 nCPM
enterocytes: 45 nCPM
respiratory basal cells: 33 nCPM
proximal tubule cells: 20 nCPM
distal convoluted tubule cells: 17 nCPM

Immune cell

naive CD4 T-cell: 3 nTPM
memory CD4 T-cell: 1.1 nTPM
naive CD8 T-cell: 0.6 nTPM
T-reg: 0.5 nTPM
basophil: 0.4 nTPM
total PBMC: 0.4 nTPM

Brain region

basal ganglia: 12 nTPM
cerebellum: 12 nTPM
cerebral cortex: 12 nTPM
white matter: 11 nTPM
amygdala: 11 nTPM
hippocampal formation: 11 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about HYKK.

Disease | GeneticClinVar

1 pathogenic / likely-pathogenic of 52 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Chronic obstructive pulmonary disease

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance): 1.15
gnomAD pLI: 0
gnomAD missense Z: 0.67
DepMap mean gene effect: 0.03
DepMap dependency class: none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

lysine catabolic process

Molecular functions

amino acid kinase activity
hydroxylysine kinase activity

Cellular components

mitochondrial matrix

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads HYKK as an antibody target. Whether an autoantibody or antibody against HYKK could matter depends on whether native HYKK is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

HYKK is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label HYKK as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Loading the interactive Seroatlas protein explorer...