RPL31 (Ribosomal Protein L31) is a component of the 60S large ribosomal subunit encoded by the RPL31 gene located on chromosome 2q14.1. This gene encodes a protein belonging to the L31E family of ribosomal proteins, which are essential for protein synthesis and have been increasingly recognized for their roles in extraribosomal functions including cellular stress response, apoptosis, and disease pathogenesis[warner2009].
RPL31 is ubiquitously expressed across human tissues, with particularly important functions in rapidly dividing cells and energy-demanding tissues such as the brain. Recent research has identified RPL31 mutations as a cause of Diamond-Blackfan anemia (DBA), expanding the spectrum of ribosomal protein genes implicated in ribosomopathies[hetzel2016]. Additionally, ribosomal protein dysfunction is increasingly recognized as a contributor to neurodegenerative diseases including Alzheimer's disease and Parkinson's disease[yoshikawa2021][1].
The RPL31 gene spans approximately 4.5 kb on chromosome 2q14.1 and consists of 5 exons. The gene encodes a protein of 125 amino acids with a molecular weight of approximately 14 kDa. The protein contains a characteristic L31E domain found in eukaryotic ribosomal proteins[dekeersmaecker2015].
RPL31 is a component of the large (60S) ribosomal subunit where it plays structural and functional roles:
The protein is localized primarily in the cytoplasm but has been detected in the nucleolus during ribosome biogenesis, reflecting its role in ribosomal assembly[zhou2015].
As a component of the 60S ribosomal subunit, RPL31 contributes to multiple aspects of translation:
Beyond translation, RPL31 has been implicated in several cellular processes:
p53 Pathway Regulation: RPL31 can interact with MDM2 and contribute to p53 stability, linking ribosomal stress to cell cycle control and apoptosis[ding2005]. This connection is particularly relevant in ribosomopathies where ribosomal stress activates p53-mediated growth arrest.
DNA Damage Response: Some studies suggest RPL31 may be recruited to sites of DNA damage, potentially participating in DNA repair processes[gauthier2023].
Cell Cycle Regulation: Through p53-dependent and independent pathways, RPL31 can influence cell proliferation and survival[dekeersmaecker2015].
RPL31 demonstrates ubiquitous expression across all human tissues:
In the central nervous system, RPL31 is expressed in:
The synaptic localization is particularly significant given the importance of local translation in synaptic plasticity and neuronal function.
RPL31 dysregulation has been observed in Alzheimer's disease through several mechanisms:
In Parkinson's disease, RPL31 connections include:
In ALS:
RPL31 has been identified as a novel gene associated with Diamond-Blackfan anemia (DBA), a rare inherited bone marrow failure syndrome characterized by:
DBA caused by RPL31 mutations follows the classic ribosomopathy mechanism: impaired ribosome biogenesis leads to ribosomal stress, p53 activation, and selective vulnerability of erythroid precursor cells[hetzel2016].
Altered RPL31 expression has been reported in several cancers:
The dual role of RPL31 as both tumor suppressor (through p53 activation) and potential oncogene highlights the complexity of ribosomal protein function in cell fate decisions[dekeersmaecker2015].
Understanding RPL31 function has inspired therapeutic strategies:
Potential therapeutic approaches for neurodegeneration include:
For DBA and related conditions:
Liu Y, et al. Ribosomal protein alterations in Parkinson's disease models. Neurobiol Aging. 2020. ↩︎