The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.
You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.
We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.
We are interested in where in or outside the cell the gene product carries out its function.
We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.
Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.
The literature reviewed here matches the UniProt-provided target: ERLIN2 (ER lipid raft-associated protein 2; “Erlin-2”), encoded by ERLIN2 in Homo sapiens, a ~40 kDa band 7/SPFH-domain ER membrane protein that forms an ERLIN1/2 hetero-oligomeric complex in cholesterol-rich ER membrane nanodomains. This description is consistent across mechanistic cell biology and disease genetics literature used in this report, supporting correct gene/protein identity alignment with UniProt accession O94905. (veronese2024erlin12scaffoldsbridge pages 1-2, manganelli2021roleoferlins pages 5-7)
“ER lipid rafts” (also described as detergent-resistant membranes/nanodomains) refer to cholesterol-enriched microdomains within the endoplasmic reticulum that organize specific proteins and lipids into functional assemblies. ERLIN2 (with ERLIN1) is widely treated as a marker and organizer of these ER raft-like domains, functioning as a non-enzymatic scaffold rather than a catalytic enzyme. (veronese2024erlin12scaffoldsbridge pages 1-2, manganelli2021roleoferlins pages 5-7)
ER-associated degradation (ERAD) removes specific ER and ER membrane proteins by ubiquitination and extraction (often via p97/VCP) followed by proteasomal degradation. ERLIN2 contributes to ERAD primarily by organizing client proteins and ubiquitination/extraction machinery within ER nanodomains, rather than directly ubiquitinating substrates. The best-supported example is activated inositol 1,4,5-trisphosphate receptors (IP3Rs), which undergo ubiquitination and ERAD after activation. (veronese2024erlin12scaffoldsbridge pages 1-2, manganelli2021roleoferlins pages 5-7)
A major theme is that ERLIN2 binds cholesterol and participates in pathways that connect ER cholesterol status to (i) regulation of SREBP (sterol regulatory element-binding proteins) activation and (ii) downstream effects on lipid storage (e.g., cholesteryl ester formation) and secretory pathway function. (veronese2024erlin12scaffoldsbridge pages 1-2, veronese2024erlin12scaffoldsbridge pages 12-12, manganelli2021roleoferlins pages 5-7)
ERLIN2 localizes to the endoplasmic reticulum membrane, enriched in cholesterol-rich ER detergent-resistant membrane fractions/nanodomains. Evidence from recent mechanistic work also supports functional presence near ER–Golgi contact regions, consistent with roles in cholesterol flux to the Golgi and regulation of Golgi morphology/secretory trafficking. (veronese2024erlin12scaffoldsbridge pages 1-2, veronese2024erlin12scaffoldsbridge pages 12-12)
ERLIN2 assembles with ERLIN1 into large ring-like hetero-oligomeric scaffold structures on the ER membrane. These scaffolds provide multivalent binding surfaces that can recruit luminal motifs and stabilize interactions among client proteins and regulators. A 2024 study (Life Science Alliance) directly connects this scaffolding role to the formation of an interaction bridge between the ER proteins TMUB1 and RNF170. (veronese2024erlin12scaffoldsbridge pages 1-2)
Visual evidence (mechanistic model and phenotype): ERLIN1/2 scaffold organization and its link to cholesterol esterification phenotypes and rescue by SOAT1 inhibition are summarized in the figures retrieved from Veronese et al. 2024. (veronese2024erlin12scaffoldsbridge media 30054738, veronese2024erlin12scaffoldsbridge media bd5fdacb, veronese2024erlin12scaffoldsbridge media 2c4467d5, veronese2024erlin12scaffoldsbridge media bf33204b, veronese2024erlin12scaffoldsbridge media c1b3c978)
RNF170 and IP3R ERAD. RNF170 is an ER membrane ubiquitin ligase implicated in ubiquitination of activated IP3Rs, with ERLIN scaffolds serving as platforms that recruit or support RNF170 function toward IP3Rs. This supports ERLIN2’s role in the IP3R ubiquitination → extraction → degradation axis, linking ERLIN2 to calcium signaling control via IP3R abundance. (veronese2024erlin12scaffoldsbridge pages 1-2, cioffi2024hereditaryspasticparaparesis pages 1-2, manganelli2021roleoferlins pages 5-7)
TMUB1, p97/VCP extraction, and ERAD coupling. TMUB1 is described as an ER-resident escort factor that promotes p97-mediated extraction of membrane proteins. The 2024 mechanistic study shows ERLIN scaffolds bridging TMUB1 and RNF170 via conserved luminal motifs, providing a concrete model for how ERLIN2-containing scaffolds can couple ubiquitination (RNF170) with extraction (TMUB1/p97) within ER nanodomains. (veronese2024erlin12scaffoldsbridge pages 1-2, veronese2024erlin12scaffoldsbridge pages 19-20)
Lipid regulation module (INSIG/SREBP/SCAP). Erlins physically interact with components of the SREBP regulatory system (SREBP–SCAP–INSIG) and are proposed to contribute to sterol-dependent retention/processing, thereby connecting ERLIN2 scaffolds to sterol-sensing control of lipid biosynthesis. (manganelli2021roleoferlins pages 5-7)
Veronese et al. (May 2024) provide direct functional evidence that ERLIN1/2 scaffolds restrict cholesterol esterification and influence Golgi morphology and the secretory pathway.
Zhu et al. (Jun 2023) used patient-derived iPSC models and identified a heterozygous ERLIN2 missense variant (p.Val71Ala) in an HSP family. Their mechanistic interpretation was that mutant ERLIN2 recruited the E3 ligase RNF213, promoting degradation of IP3R1, which lowered intracellular free Ca2+, induced ER-stress-mediated apoptosis, and suppressed MAPK signaling, reducing proliferation in patient-derived neural cells. This work proposes a specific autosomal-dominant disease mechanism via altered IP3R abundance and calcium homeostasis. (zhu2023disruptionofintracellular pages 1-2)
Two 2024 clinical genetics studies expand phenotype and inheritance considerations for ERLIN2-related spastic paraplegia:
The 2024 scaffold study explicitly links ERLIN complex biology (TMUB1/RNF170 and cholesterol esterification control) to variants previously linked to hereditary spastic paraplegia, framing disease as potentially involving disruption of nanodomain scaffold interactions that couple lipid handling and ERAD/client processing. (veronese2024erlin12scaffoldsbridge pages 1-2, veronese2024erlin12scaffoldsbridge pages 12-12)
ERLIN2 is now a recognized disease gene in hereditary spastic paraplegia gene panels and exome/genome sequencing workflows; the 2024 Italian series provides real-world scale metrics (944 suspected HSP patients screened over 8 years) and highlights the practical diagnostic implication that HSP gene panels may be relevant even in familial ALS-like presentations due to observed phenoconversion in some ERLIN2-linked cases. (cioffi2024hereditaryspasticparaparesis pages 1-2)
While no approved ERLIN2-targeted therapy exists in the evidence reviewed, Veronese et al. provide a proof-of-principle that modulating downstream lipid metabolism can correct ERLIN-loss phenotypes: SOAT1 inhibition (avasimibe) rescued lipid droplet and Golgi phenotypes in ERLIN-deficient cells. This suggests a potential translational direction (pathway-level intervention rather than direct ERLIN2 targeting) for disorders where cholesterol esterification imbalance is a driver. (veronese2024erlin12scaffoldsbridge media 30054738, veronese2024erlin12scaffoldsbridge media bf33204b)
Open Targets aggregates literature-based evidence linking ERLIN2 to hereditary spastic paraplegia 18 and broader hereditary spastic paraplegia disease concepts, as well as cancer-related associations (likely reflecting ERLIN2 amplification/ER-stress literature). This is useful for prioritization but should be interpreted as an evidence aggregation layer rather than direct mechanistic proof. (OpenTargets Search: -ERLIN2)
The most defensible primary function for ERLIN2 is that of an ER membrane nanodomain scaffold/adaptor that integrates two major functional themes:
This dual role provides a plausible bridge between (i) neurologic phenotypes driven by altered Ca2+ homeostasis (via IP3R regulation) and (ii) broader cell biology phenotypes involving secretory pathway dysfunction and lipid droplet accumulation.
Two non-mutually exclusive mechanisms are supported:
The following table provides a structured evidence map linking ERLIN2 functional annotation components to key sources, including URLs/DOIs and explicitly captured quantitative points.
| Aspect | Key findings | Key sources (author year, journal) | URL/DOI |
|---|---|---|---|
| Identity/domain/localization | ERLIN2 is the verified human protein encoded by ERLIN2 (UniProt O94905), an ER lipid raft-associated membrane protein in the band 7/SPFH family that hetero-oligomerizes with ERLIN1. It localizes mainly to cholesterol-rich ER detergent-resistant nanodomains and has also been linked to ER–Golgi contact regions and, under some conditions, MAM-associated rafts (veronese2024erlin12scaffoldsbridge pages 1-2, manganelli2021roleoferlins pages 5-7). | Veronese 2024, Life Science Alliance; Manganelli 2021, Cells | https://doi.org/10.26508/lsa.202402620 ; https://doi.org/10.3390/cells10092408 |
| Complex/partners | ERLIN2 forms large ring-shaped ERLIN1/2 complexes (likely ~24 subunits) that scaffold membrane proteins. Reported partners include ERLIN1, RNF170, TMUB1, TMEM259, INSIG1, FAF2, VCP/p97, and associations with other ERAD ligases. A 2024 study showed ERLIN scaffolds bridge TMUB1 and RNF170 through a conserved luminal motif that binds adjacent ERLIN SPFH interfaces (veronese2024erlin12scaffoldsbridge pages 1-2, veronese2024erlin12scaffoldsbridge pages 12-12, veronese2024erlin12scaffoldsbridge pages 19-20). | Veronese 2024, Life Science Alliance | https://doi.org/10.26508/lsa.202402620 |
| Pathways/mechanism | Best-supported mechanism: ERLIN2 acts as a non-enzymatic ER membrane scaffold/adaptor in ER-associated degradation (ERAD), especially for activated IP3 receptors (IP3Rs). ERLIN2 helps recruit RNF170 for IP3R ubiquitination/degradation and binds cholesterol and PI3P, supporting microdomain assembly and client handling. ERLINs also influence SREBP/INSIG/SCAP regulation, HMG-CoA reductase turnover, and cholesterol partitioning/esterification, thereby affecting Golgi morphology and the secretory pathway (veronese2024erlin12scaffoldsbridge pages 1-2, veronese2024erlin12scaffoldsbridge pages 12-12, manganelli2021roleoferlins pages 5-7). | Veronese 2024, Life Science Alliance; Manganelli 2021, Cells | https://doi.org/10.26508/lsa.202402620 ; https://doi.org/10.3390/cells10092408 |
| Disease links | Human genetics strongly links ERLIN2 to SPG18 / hereditary spastic paraplegia (HSP) with autosomal recessive and some autosomal dominant presentations. Clinical expansion includes developmental delay, seizures, contractures, hearing loss, and reported HSP-to-ALS phenoconversion in some families. Recent work also proposed a dominant mechanism in which mutant ERLIN2 alters IP3R control and Ca2+ homeostasis (cioffi2024hereditaryspasticparaparesis pages 1-2, zhu2023disruptionofintracellular pages 1-2, trinchillo2024expandingspg18clinical pages 8-9, OpenTargets Search: -ERLIN2). | Cioffi 2024, Neurological Sciences; Zhu 2023, Human Mutation; Trinchillo 2024, Neurological Sciences; Open Targets | https://doi.org/10.1007/s10072-024-07423-w ; https://doi.org/10.1155/2023/4834423 ; https://doi.org/10.1007/s10072-024-07500-0 ; https://platform.opentargets.org/target/ENSG00000147475 |
| Key quantitative findings | Explicit quantitative snippets reported in accessible evidence: HeLa ERLIN double-knockout cells showed a tendency toward increased SOAT1 abundance (log2FC = 0.40; q = 0.07), consistent with increased cholesterol esterification pressure; in one 2024 SPG18 clinical series, 2 of 5 cases showed HSP→ALS phenoconversion; the same report noted 944 clinically suspected HSP patients screened over 8 years in one laboratory workflow (veronese2024erlin12scaffoldsbridge pages 12-12, cioffi2024hereditaryspasticparaparesis pages 1-2). | Veronese 2024, Life Science Alliance; Cioffi 2024, Neurological Sciences | https://doi.org/10.26508/lsa.202402620 ; https://doi.org/10.1007/s10072-024-07423-w |
| 2023–2024 mechanistic update | A 2023 patient-derived iPSC study of ERLIN2 p.Val71Ala proposed that mutant ERLIN2 recruits RNF213 to drive IP3R1 degradation, lowering intracellular free Ca2+, triggering ER-stress apoptosis, and suppressing MAPK signaling/cell proliferation. A 2024 cell-biology study extended ERLIN function beyond classical ERAD, showing ERLIN scaffolds restrict cholesterol esterification and favor ER-to-Golgi cholesterol transport to support secretory-pathway organization (zhu2023disruptionofintracellular pages 1-2, veronese2024erlin12scaffoldsbridge pages 1-2). | Zhu 2023, Human Mutation; Veronese 2024, Life Science Alliance | https://doi.org/10.1155/2023/4834423 ; https://doi.org/10.26508/lsa.202402620 |
Table: This table summarizes the core functional annotation evidence for human ERLIN2, emphasizing verified identity, molecular mechanism, disease relevance, and the most explicit quantitative findings from recent literature.
Some mechanistic claims widely discussed in the ERLIN literature (e.g., detailed kinetics of IP3R ubiquitination steps, full substrate lists beyond IP3R/HMGR, and structural resolution of the oligomer) are referenced in the review and scaffold work but were not all available as fully inspectable primary evidence snippets in the retrieved text corpus for this run. Therefore, the report emphasizes mechanisms directly supported by the retrieved full-text evidence and figures. (veronese2024erlin12scaffoldsbridge pages 1-2, manganelli2021roleoferlins pages 5-7)
References
(veronese2024erlin12scaffoldsbridge pages 1-2): Matteo Veronese, Sebastian Kallabis, Alexander Tobias Kaczmarek, Anushka Das, Lennart Robers, Simon Schumacher, Alessia Lofrano, Susanne Brodesser, Stefan Müller, Kay Hofmann, Marcus Krüger, and Elena I Rugarli. Erlin1/2 scaffolds bridge tmub1 and rnf170 and restrict cholesterol esterification to regulate the secretory pathway. Life Science Alliance, 7:e202402620, May 2024. URL: https://doi.org/10.26508/lsa.202402620, doi:10.26508/lsa.202402620. This article has 8 citations and is from a peer-reviewed journal.
(manganelli2021roleoferlins pages 5-7): Valeria Manganelli, Agostina Longo, Vincenzo Mattei, Serena Recalchi, Gloria Riitano, Daniela Caissutti, Antonella Capozzi, Maurizio Sorice, Roberta Misasi, and Tina Garofalo. Role of erlins in the control of cell fate through lipid rafts. Cells, 10:2408, Sep 2021. URL: https://doi.org/10.3390/cells10092408, doi:10.3390/cells10092408. This article has 42 citations.
(veronese2024erlin12scaffoldsbridge pages 12-12): Matteo Veronese, Sebastian Kallabis, Alexander Tobias Kaczmarek, Anushka Das, Lennart Robers, Simon Schumacher, Alessia Lofrano, Susanne Brodesser, Stefan Müller, Kay Hofmann, Marcus Krüger, and Elena I Rugarli. Erlin1/2 scaffolds bridge tmub1 and rnf170 and restrict cholesterol esterification to regulate the secretory pathway. Life Science Alliance, 7:e202402620, May 2024. URL: https://doi.org/10.26508/lsa.202402620, doi:10.26508/lsa.202402620. This article has 8 citations and is from a peer-reviewed journal.
(veronese2024erlin12scaffoldsbridge media 30054738): Matteo Veronese, Sebastian Kallabis, Alexander Tobias Kaczmarek, Anushka Das, Lennart Robers, Simon Schumacher, Alessia Lofrano, Susanne Brodesser, Stefan Müller, Kay Hofmann, Marcus Krüger, and Elena I Rugarli. Erlin1/2 scaffolds bridge tmub1 and rnf170 and restrict cholesterol esterification to regulate the secretory pathway. Life Science Alliance, 7:e202402620, May 2024. URL: https://doi.org/10.26508/lsa.202402620, doi:10.26508/lsa.202402620. This article has 8 citations and is from a peer-reviewed journal.
(veronese2024erlin12scaffoldsbridge media bd5fdacb): Matteo Veronese, Sebastian Kallabis, Alexander Tobias Kaczmarek, Anushka Das, Lennart Robers, Simon Schumacher, Alessia Lofrano, Susanne Brodesser, Stefan Müller, Kay Hofmann, Marcus Krüger, and Elena I Rugarli. Erlin1/2 scaffolds bridge tmub1 and rnf170 and restrict cholesterol esterification to regulate the secretory pathway. Life Science Alliance, 7:e202402620, May 2024. URL: https://doi.org/10.26508/lsa.202402620, doi:10.26508/lsa.202402620. This article has 8 citations and is from a peer-reviewed journal.
(veronese2024erlin12scaffoldsbridge media 2c4467d5): Matteo Veronese, Sebastian Kallabis, Alexander Tobias Kaczmarek, Anushka Das, Lennart Robers, Simon Schumacher, Alessia Lofrano, Susanne Brodesser, Stefan Müller, Kay Hofmann, Marcus Krüger, and Elena I Rugarli. Erlin1/2 scaffolds bridge tmub1 and rnf170 and restrict cholesterol esterification to regulate the secretory pathway. Life Science Alliance, 7:e202402620, May 2024. URL: https://doi.org/10.26508/lsa.202402620, doi:10.26508/lsa.202402620. This article has 8 citations and is from a peer-reviewed journal.
(veronese2024erlin12scaffoldsbridge media bf33204b): Matteo Veronese, Sebastian Kallabis, Alexander Tobias Kaczmarek, Anushka Das, Lennart Robers, Simon Schumacher, Alessia Lofrano, Susanne Brodesser, Stefan Müller, Kay Hofmann, Marcus Krüger, and Elena I Rugarli. Erlin1/2 scaffolds bridge tmub1 and rnf170 and restrict cholesterol esterification to regulate the secretory pathway. Life Science Alliance, 7:e202402620, May 2024. URL: https://doi.org/10.26508/lsa.202402620, doi:10.26508/lsa.202402620. This article has 8 citations and is from a peer-reviewed journal.
(veronese2024erlin12scaffoldsbridge media c1b3c978): Matteo Veronese, Sebastian Kallabis, Alexander Tobias Kaczmarek, Anushka Das, Lennart Robers, Simon Schumacher, Alessia Lofrano, Susanne Brodesser, Stefan Müller, Kay Hofmann, Marcus Krüger, and Elena I Rugarli. Erlin1/2 scaffolds bridge tmub1 and rnf170 and restrict cholesterol esterification to regulate the secretory pathway. Life Science Alliance, 7:e202402620, May 2024. URL: https://doi.org/10.26508/lsa.202402620, doi:10.26508/lsa.202402620. This article has 8 citations and is from a peer-reviewed journal.
(cioffi2024hereditaryspasticparaparesis pages 1-2): Ettore Cioffi, Valeria Gioiosa, Alessandra Tessa, Antonio Petrucci, Rosanna Trovato, Filippo Maria Santorelli, and Carlo Casali. Hereditary spastic paraparesis type 18 (spg18): new erlin2 variants in a series of italian patients, shedding light upon genetic and phenotypic variability. Neurological Sciences, 45:3845-3852, Mar 2024. URL: https://doi.org/10.1007/s10072-024-07423-w, doi:10.1007/s10072-024-07423-w. This article has 3 citations and is from a peer-reviewed journal.
(veronese2024erlin12scaffoldsbridge pages 19-20): Matteo Veronese, Sebastian Kallabis, Alexander Tobias Kaczmarek, Anushka Das, Lennart Robers, Simon Schumacher, Alessia Lofrano, Susanne Brodesser, Stefan Müller, Kay Hofmann, Marcus Krüger, and Elena I Rugarli. Erlin1/2 scaffolds bridge tmub1 and rnf170 and restrict cholesterol esterification to regulate the secretory pathway. Life Science Alliance, 7:e202402620, May 2024. URL: https://doi.org/10.26508/lsa.202402620, doi:10.26508/lsa.202402620. This article has 8 citations and is from a peer-reviewed journal.
(zhu2023disruptionofintracellular pages 1-2): Xin Zhu, Xiaoyin Tan, Junwen Wang, Limeng Dai, Jia Li, Xingying Guan, Ziyi Wang, Mao Zhang, Junyan Hu, Yun Bai, and Hongen Guo. Disruption of intracellular calcium homeostasis leads to erlin2-linked hereditary spastic paraplegia in patient-derived stem cell models. Human Mutation, 2023:1-14, Jun 2023. URL: https://doi.org/10.1155/2023/4834423, doi:10.1155/2023/4834423. This article has 1 citations and is from a domain leading peer-reviewed journal.
(trinchillo2024expandingspg18clinical pages 8-9): Assunta Trinchillo, Valeria Valente, Marcello Esposito, Miriana Migliaccio, Aniello Iovino, Michele Picciocchi, Nunzia Cuomo, Carmela Caccavale, Cristofaro Nocerino, Laura De Rosa, Elena Salvatore, Giovanna Maria Pierantoni, Valeria Menchise, Simona Paladino, and Chiara Criscuolo. Expanding spg18 clinical spectrum: autosomal dominant mutation causes complicated hereditary spastic paraplegia in a large family. Neurological Sciences, 45:4373-4381, Apr 2024. URL: https://doi.org/10.1007/s10072-024-07500-0, doi:10.1007/s10072-024-07500-0. This article has 2 citations and is from a peer-reviewed journal.
(OpenTargets Search: -ERLIN2): Open Targets Query (-ERLIN2, 5 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.