HSDL2
Hydroxysteroid dehydrogenase-like protein 2
Also known as: C9orf99, HSDL2_HUMAN, SDR13C1
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- Q6YN16
- Gene
- HSDL2
- Ensembl
- ENSG00000119471
- Chromosome
- 9
- Canonical length
- 418 aa
- Protein class
- Plasma proteins, Predicted intracellular proteins
- Subcellular location
- Mitochondria
OverviewNCBI Gene
Predicted to enable oxidoreductase activity. Involved in cholesterol homeostasis. Located in mitochondrion and peroxisome. [provided by Alliance of Genome Resources, Jul 2025]
Canonical amino-acid sequenceUniProt
418 residues, UniProt reviewed canonical sequence.
>Q6YN16|HSDL2
1 MLPNTGRLAG CTVFITGASR GIGKAIALKA AKDGANIVIA AKTAQPHPKL LGTIYTAAEE
61 IEAVGGKALP CIVDVRDEQQ ISAAVEKAIK KFGGIDILVN NASAISLTNT LDTPTKRLDL
121 MMNVNTRGTY LASKACIPYL KKSKVAHILN ISPPLNLNPV WFKQHCAYTI AKYGMSMYVL
181 GMAEEFKGEI AVNALWPKTA IHTAAMDMLG GPGIESQCRK VDIIADAAYS IFQKPKSFTG
241 NFVIDENILK EEGIENFDVY AIKPGHPLQP DFFLDEYPEA VSKKVESTGA VPEFKEEKLQ
301 LQPKPRSGAV EETFRIVKDS LSDDVVKATQ AIYLFELSGE DGGTWFLDLK SKGGNVGYGE
361 PSDQADVVMS MTTDDFVKMF SGKLKPTMAF MSGKLKIKGN MALAIKLEKL MNQMNARLLocalizationUniProt · AlphaFold · HPA
Whether an antibody against HSDL2 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)
- 0.26
- Highest tissue expression
- 169 nTPM
Expression across tissuesHPA
Tissue
- tongue: 169 nTPM
- skeletal muscle: 142 nTPM
- liver: 139 nTPM
- heart muscle: 86 nTPM
- adipose tissue: 72 nTPM
- kidney: 64 nTPM
Single-cell type
- neutrophils: 470 nCPM
- myonuclei: 435 nCPM
- adipocytes: 296 nCPM
- late spermatids: 233 nCPM
- hepatocytes: 232 nCPM
- adrenal cortex cells: 231 nCPM
Immune cell
- basophil: 55 nTPM
- neutrophil: 48 nTPM
- eosinophil: 33 nTPM
- non-classical monocyte: 12 nTPM
- myeloid DC: 9.5 nTPM
- plasmacytoid DC: 9.4 nTPM
Brain region
- hypothalamus: 51 nTPM
- midbrain: 50 nTPM
- thalamus: 48 nTPM
- basal ganglia: 43 nTPM
- amygdala: 39 nTPM
- white matter: 39 nTPM
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)
- 0.88
- gnomAD pLI
- 0
- gnomAD missense Z
- 0.9
- DepMap mean gene effect
- -0.05
- DepMap dependency class
- selective
Cancer expressionTCGA
Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).
OntologyGO
Biological processes
Molecular functions
Cellular components
Protein domainsUniProt · Pfam · InterPro
KeywordsUniProt
Antibody and autoantibody relevanceSeroatlas analysis
Seroatlas reads HSDL2 as an antibody target. Whether an autoantibody or antibody against HSDL2 could matter depends on whether native HSDL2 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
HSDL2 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 HSDL2 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
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