Seroatlas · Human Serome Atlas

MRPS33

Small ribosomal subunit protein mS33

Also known as: CGI-139, RT33_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: Q9Y291
Gene: MRPS33
Ensembl: ENSG00000090263
Chromosome: 7
Canonical length: 106 aa
Protein class: Predicted intracellular proteins, Ribosomal proteins

OverviewNCBI Gene

Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and help in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. They have an estimated 75% protein to rRNA composition compared to prokaryotic ribosomes, where this ratio is reversed. Another difference between mammalian mitoribosomes and prokaryotic ribosomes is that the latter contain a 5S rRNA. Among different species, the proteins comprising the mitoribosome differ greatly in sequence, and sometimes in biochemical properties, which prevents easy recognition by sequence homology. The 28S subunit of the mammalian mitoribosome may play a crucial and characteristic role in translation initiation. This gene encodes a 28S subunit protein that is one of the more highly conserved mitochondrial ribosomal proteins among mammals, Drosophila and C. elegans. Splice variants that differ in the 5' UTR have been found for this gene; all variants encode the same protein. Pseudogenes corresponding to this gene are found on chromosomes 1q, 4p, 4q, and 20q [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

106 residues, UniProt reviewed canonical sequence.

>Q9Y291|MRPS33
     1  MSSLSEYAFR MSRLSARLFG EVTRPTNSKS MKVVKLFSEL PLAKKKETYD WYPNHHTYAE
    61  LMQTLRFLGL YRDEHQDFMD EQKRLKKLRG KEKPKKGEGK RAAKRK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against MRPS33 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): 0.52
Highest tissue expression: 163 nTPM

Expression across tissuesHPA

Tissue

skeletal muscle: 163 nTPM
tongue: 160 nTPM
heart muscle: 108 nTPM
choroid plexus: 87 nTPM
liver: 78 nTPM
parathyroid gland: 76 nTPM

Single-cell type

late primary spermatocytes: 303 nCPM
hepatocytes: 250 nCPM
parietal cells: 239 nCPM
esophageal suprabasal cells: 234 nCPM
epididymal principal cells: 229 nCPM
esophageal basal cells: 221 nCPM

Immune cell

naive CD4 T-cell: 99 nTPM
plasmacytoid DC: 94 nTPM
memory B-cell: 86 nTPM
memory CD4 T-cell: 86 nTPM
naive CD8 T-cell: 84 nTPM
NK-cell: 80 nTPM

Brain region

hypothalamus: 29 nTPM
pons: 29 nTPM
choroid plexus: 28 nTPM
white matter: 28 nTPM
spinal cord: 26 nTPM
medulla oblongata: 26 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): 1.62
gnomAD pLI: 0
gnomAD missense Z: -0.04
DepMap mean gene effect: -0.15
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 9% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

structural constituent of ribosome

Cellular components

Protein domainsUniProt · Pfam · InterPro

Small ribosomal subunit protein mS33
Mitochondrial ribosomal subunit S27

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of MRPS33 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 MRPS33 as an antibody target. Whether an autoantibody or antibody against MRPS33 could matter depends on whether native MRPS33 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

MRPS33 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 MRPS33 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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