Seroatlas · Human Serome Atlas

PNO1

RNA-binding protein PNO1

Also known as: KHRBP1, PNO1_HUMAN, RRP20

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

Protein identityUniProt · HPA

UniProt accession: Q9NRX1
Gene: PNO1
Ensembl: ENSG00000115946
Chromosome: 2
Canonical length: 252 aa
Protein class: Plasma proteins, Predicted intracellular proteins
Subcellular location: Nucleoplasm,Nucleoli

OverviewNCBI Gene

Enables RNA binding activity. Involved in ribosomal small subunit biogenesis. Located in nucleolus and nucleoplasm. Part of small-subunit processome. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

252 residues, UniProt reviewed canonical sequence.

>Q9NRX1|PNO1
     1  MESEMETQSA RAEEGFTQVT RKGGRRAKKR QAEQLSAAGE GGDAGRMDTE EARPAKRPVF
    61  PPLCGDGLLS GKEETRKIPV PANRYTPLKE NWMKIFTPIV EHLGLQIRFN LKSRNVEIRT
   121  CKETKDVSAL TKAADFVKAF ILGFQVEDAL ALIRLDDLFL ESFEITDVKP LKGDHLSRAI
   181  GRIAGKGGKT KFTIENVTRT RIVLADVKVH ILGSFQNIKM ARTAICNLIL GNPPSKVYGN
   241  IRAVASRSAD RF

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against PNO1 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): 0.43
Highest tissue expression: 19 nTPM

Expression across tissuesHPA

Tissue

skeletal muscle: 19 nTPM
urinary bladder: 19 nTPM
bone marrow: 18 nTPM
retina: 17 nTPM
adipose tissue: 15 nTPM
adrenal gland: 13 nTPM

Single-cell type

basal keratinocytes: 92 nCPM
suprabasal keratinocytes: 69 nCPM
erythrocyte progenitors: 68 nCPM
esophageal basal cells: 65 nCPM
rod photoreceptor cells: 65 nCPM
syncytiotrophoblasts: 62 nCPM

Immune cell

total PBMC: 21 nTPM
memory B-cell: 19 nTPM
MAIT T-cell: 19 nTPM
intermediate monocyte: 18 nTPM
myeloid DC: 17 nTPM
naive CD4 T-cell: 16 nTPM

Brain region

hippocampal formation: 20 nTPM
cerebral cortex: 20 nTPM
basal ganglia: 12 nTPM
hypothalamus: 11 nTPM
white matter: 11 nTPM
midbrain: 10 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): 0.67
gnomAD pLI: 0.23
gnomAD missense Z: -0.23
DepMap mean gene effect: -1.07
DepMap dependency class: common

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 8% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

ribosomal small subunit biogenesis

Molecular functions

RNA binding

Cellular components

Protein domainsUniProt · Pfam · InterPro

K Homology domain
K Homology domain, type 1 superfamily
PNO1, second type I KH domain
PNO1, first type I KH domain
Eukaryotic type KH-domain (KH-domain type I)

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of PNO1 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads PNO1 as an antibody target. Whether an autoantibody or antibody against PNO1 could matter depends on whether native PNO1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

PNO1 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 PNO1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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