Exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling.', 'Component of the 40S subunit of the ribosome. (updated: Dec. 11, 2019)

Protein identification was indicated in the following studies:

Methods

The following articles were analysed to gather the proteome content of erythrocytes.

The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.

Publication	Identification ¹	Uniprot mapping ²	Not mapped / Obsolete	TrEMBL	Swiss-Prot
Goodman (2013)	2289 (gene list)	2278	53	20599	2269
Lange (2014)	1234	1234	7	28	1224
Hegedus (2015)	2638	2622	0	235	2387
Wilson (2016)	1658	1528	170	291	1068
d'Alessandro (2017)	1826	1817	2	0	1815
Bryk (2017)	2090	2060	10	108	1942
Chu (2018)	1853	1804	55	362	1387

¹ as available in the article and/or in supplementary material
² uniprot mapping returns all protein isoforms as one entry

The compilation of older studies can be retrieved from the Red Blood Cell Collection database.

The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.

No sequence conservation computed yet.

Protein sequence (FASTA)

Protein coevolution profile (FreeContact)

Multiple Sequence Alignment (Muscle)

This protein is annotated as membranous in Gene Ontology.

Total structural coverage: 100%

Model score: 0

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Biological Process

Activation of MAPK activity

Aggrephagy

Amyloid fibril formation

Anaphase-promoting complex-dependent catabolic process

Antigen processing and presentation of exogenous peptide antigen via MHC class I

Antigen processing and presentation of exogenous peptide antigen via MHC class I, TAP-dependent

Antigen processing and presentation of peptide antigen via MHC class I

Apoptotic process

Apoptotic signaling pathway

Carbohydrate metabolic process

Cellular iron ion homeostasis

Cellular protein metabolic process

Cellular response to hypoxia

Circadian rhythm

Cytokine-mediated signaling pathway

Cytoplasmic pattern recognition receptor signaling pathway

Cytoplasmic translation

DNA damage response, detection of DNA damage

DNA damage response, signal transduction by p53 class mediator resulting in cell cycle arrest

DNA repair

Endoplasmic reticulum mannose trimming

Endosomal transport

Entry of bacterium into host cell

Epidermal growth factor receptor signaling pathway

ERBB2 signaling pathway

Error-free translesion synthesis

Error-prone translesion synthesis

Fc-epsilon receptor signaling pathway

Fibroblast growth factor receptor signaling pathway

G1/S transition of mitotic cell cycle

G2/M transition of mitotic cell cycle

Gene expression

Global genome nucleotide-excision repair

Glucose metabolic process

Glycogen biosynthetic process

I-kappaB kinase/NF-kappaB signaling

Innate immune response

Interleukin-1-mediated signaling pathway

Interstrand cross-link repair

Intracellular transport of virus

Ion transmembrane transport

JNK cascade

Macroautophagy

MAPK cascade

Membrane organization

Mitotic cell cycle

Modification-dependent protein catabolic process

Modulation by symbiont of host defense response

MyD88-dependent toll-like receptor signaling pathway

MyD88-independent toll-like receptor signaling pathway

Negative regulation of apoptotic process

Negative regulation of canonical Wnt signaling pathway

Negative regulation of epidermal growth factor receptor signaling pathway

Negative regulation of G2/M transition of mitotic cell cycle

Negative regulation of Notch signaling pathway

Negative regulation of transcription by RNA polymerase II

Negative regulation of transforming growth factor beta receptor signaling pathway

Negative regulation of type I interferon production

Neurotrophin TRK receptor signaling pathway

NIK/NF-kappaB signaling

Notch receptor processing

Notch signaling pathway

Nuclear-transcribed mRNA catabolic process, nonsense-mediated decay

Nucleotide-binding domain, leucine rich repeat containing receptor signaling pathway

Nucleotide-binding oligomerization domain containing signaling pathway

Nucleotide-excision repair, DNA damage recognition

Nucleotide-excision repair, DNA duplex unwinding

Nucleotide-excision repair, DNA gap filling

Nucleotide-excision repair, DNA incision

Nucleotide-excision repair, DNA incision, 5'-to lesion

Nucleotide-excision repair, preincision complex assembly

Obsolete negative regulation of ubiquitin-protein ligase activity involved in mitotic cell cycle

Obsolete positive regulation of ubiquitin-protein ligase activity involved in regulation of mitotic cell cycle transition

Obsolete regulation of ubiquitin-protein ligase activity involved in mitotic cell cycle

Pathogenesis

Positive regulation of apoptotic process

Positive regulation of canonical Wnt signaling pathway

Positive regulation of epidermal growth factor receptor signaling pathway

Positive regulation of I-kappaB kinase/NF-kappaB signaling

Positive regulation of NF-kappaB transcription factor activity

Positive regulation of transcription by RNA polymerase II

Positive regulation of type I interferon production

Pre-replicative complex assembly

Proteasome-mediated ubiquitin-dependent protein catabolic process

Protein deubiquitination

Protein folding

Protein localization

Protein polyubiquitination

Protein targeting to peroxisome

Protein ubiquitination

Protein ubiquitination involved in ubiquitin-dependent protein catabolic process

Regulation of apoptotic process

Regulation of exit from mitosis

Regulation of hematopoietic stem cell differentiation

Regulation of mRNA stability

Regulation of necroptotic process

Regulation of signal transduction by p53 class mediator

Regulation of transcription from RNA polymerase II promoter in response to hypoxia

Regulation of tumor necrosis factor-mediated signaling pathway

Regulation of type I interferon production

RRNA processing

SCF-dependent proteasomal ubiquitin-dependent protein catabolic process

Small molecule metabolic process

SRP-dependent cotranslational protein targeting to membrane

Stimulatory C-type lectin receptor signaling pathway

Stress-activated MAPK cascade

T cell receptor signaling pathway

Toll-like receptor 10 signaling pathway

Toll-like receptor 2 signaling pathway

Toll-like receptor 3 signaling pathway

Toll-like receptor 4 signaling pathway

Toll-like receptor 5 signaling pathway

Toll-like receptor 9 signaling pathway

Toll-like receptor signaling pathway

Toll-like receptor TLR1:TLR2 signaling pathway

Toll-like receptor TLR6:TLR2 signaling pathway

Transcription initiation from RNA polymerase II promoter

Transcription, DNA-templated

Transcription-coupled nucleotide-excision repair

Transforming growth factor beta receptor signaling pathway

Translation

Translational elongation

Translational initiation

Translational termination

Translesion synthesis

Transmembrane transport

TRIF-dependent toll-like receptor signaling pathway

Tumor necrosis factor-mediated signaling pathway

Viral life cycle

Viral process

Viral protein processing

Viral transcription

Viral translation

Virion assembly

Wnt signaling pathway

Wnt signaling pathway, planar cell polarity pathway

Cellular Component

Cytoplasm

Cytosol

Cytosolic ribosome

Cytosolic small ribosomal subunit

Endocytic vesicle membrane

Endoplasmic reticulum membrane

Endoplasmic reticulum quality control compartment

Endosome membrane

Extracellular exosome

Extracellular space

Host cell

Membrane

Mitochondrial outer membrane

Myelin sheath

Nucleolus

Nucleoplasm

Nucleus

Plasma membrane

Small ribosomal subunit

Vesicle

Molecular Function

Metal ion binding

Poly(A) RNA binding

Protein tag

RNA binding

Structural constituent of ribosome

Ubiquitin protein ligase binding

The reference OMIM entry for this protein is 191343

Ribosomal protein s27a; rps27a
Ubiquitin a-80-residue ribosomal protein fusion product; uba80
Human ubiquitin carboxyl extension protein, 80-residue; hubcep80; cep80
Ubiquitin carboxyl extension protein 1; ubcep1

Ubiquitin is a highly conserved 76-amino acid protein that plays a key role in protein degradation. Ubiquitin is synthesized as precursor proteins that consist either of polyubiquitin chains that are cleaved into moieties of the UBB (191339) or UBC (191340) types, or single ubiquitin moieties fused 5-prime to unrelated carboxyl extension proteins (UBA type) such as UBA52 (191321) and UBA80 (RPS27A).

CLONING

By screening a liver cDNA library with probes for IGF1 (147440), Lund et al. (1985) obtained a partial cDNA encoding all but the N-terminal 4 amino acids of RPS27A. The deduced 156-amino acid protein contains ubiquitin plus an 80-residue C-terminal extension. Northern blot analysis revealed expression of an 0.6-kb transcript in liver and mammary carcinoma cells. Pancre et al. (1991) obtained a full-length cDNA encoding RPS27A by screening a Jurkat cDNA library for a platelet activity suppressive lymphokine. Using differential screening of mammary carcinoma and fibroadenoma tumors, Adams et al. (1992) isolated a cDNA encoding RPS27A, which they called HUBCEP80. They detected higher levels of RPS27A in nonmalignant fibroadenoma.

BIOCHEMICAL FEATURES

Monia et al. (1989) developed a system for expression of human ubiquitin carboxyl extension proteins in prokaryotic and eukaryotic hosts. When expressed in Saccharomyces cerevisiae, the intact proteins were rapidly processed to free ubiquitin monomer and extension protein. Furthermore, expression in this host conferred a slow growth phenotype mediated by the extension protein. Expression in E. coli did not result in processing of the fusion proteins. However, when the expressed fusion proteins were purified from E. coli and incubated with a rabbit reticulocyte extract, the proteins were rapidly processed to free ubiquitin monomer and extension protein. These results showed that human ubiquitin carboxyl extension proteins are processed to ubiquitin and extension protein when expressed in eukaryotic but not prokaryotic cells and that pre- and cotranslational events are not necessary for their processing.

GENE STRUCTURE

By PCR and YAC analysis, Kirschner and Stratakis (2000) determined that the RPS27A gene contains 6 exons, with the initiator ATG in exon 2, and spans approximately 2.9 kb. Promoter analysis identified a GC-rich region with an SP1 box but no TATA or CAAT boxes.

MAPPING

By radiation hybrid and physical mapping analyses, Kirschner and Stratakis (2000) mapped the RPS27A gene to 2p16. They identified a pseudogene on chromosome 17. ... More on the omim web site

Subscribe to this protein entry history

Jan. 22, 2020: Protein entry updated
Automatic update: Entry updated from uniprot information.

Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated

Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated

March 25, 2017: Additional information
No protein expression data in P. Mayeux work for RPS27A

March 16, 2016: Protein entry updated
Automatic update: OMIM entry 191343 was added.

Ubiquitin-40S ribosomal protein S27a (RPS27A)