SCP2D1 (Q9UJQ7) – Sterol‐Binding Domain Protein in Human OpenAI o3-deep-research-2025-06-26 81 citations 2025-11-03T21:57:12.732306

SCP2D1 (Q9UJQ7) – Sterol‐Binding Domain Protein in Human

Identity and Domain Structure

SCP2D1 (Sterol Carrier Protein 2 Domain Containing 1) is a human protein-coding gene (also known as C20orf79 or “sterol carrier protein 2-like protein”) that encodes a small intracellular protein of about 156 amino acids (www.genecards.org) (www.scbt.com). As the name suggests, the SCP2D1 protein consists largely of a sterol carrier protein type 2 (SCP2) sterol-binding domain, a conserved module known for binding lipids. This domain is homologous to that of the well-characterized sterol carrier protein-2 (SCP2) and is believed to confer lipid-binding and transfer functionality (www.scbt.com). Notably, SCP2D1 is poorly characterized in the literature – it has no dedicated UniProt functional summary and has not been extensively studied experimentally (www.scbt.com). Its annotation as an SCP2 domain-containing protein is based on sequence homology and domain prediction, rather than direct experimental characterization (www.scbt.com) (www.scbt.com).

Structurally, the SCP2 domain in SCP2D1 forms a compact globular fold with a large hydrophobic cavity that accommodates lipid molecules. Crystallographic and NMR studies of SCP2 domains (from other organisms) show that the interior of this domain is lined with non-polar amino acids and typically lacks ordered water, allowing it to bind hydrophobic ligands like cholesterol or fatty acids (pubmed.ncbi.nlm.nih.gov). This contrasts with other lipid-binding proteins (e.g. fatty-acid binding proteins) which have more polar cavities; the SCP2 domain’s apolar cavity underpins its broad, non-specific lipid-binding capacity (pubmed.ncbi.nlm.nih.gov). In line with these structural insights, SCP2D1 is predicted to bind sterols (such as cholesterol) and possibly long-chain fatty acyl-CoAs or other lipids, akin to its SCP2 domain relatives. It does not contain known catalytic motifs and is not an enzyme; instead, it is classified as a carrier/transfer protein for lipids within the cell.

Biochemical Function and Mechanism

By analogy to SCP2 (the paralogous protein), SCP2D1 is thought to function as a non-specific lipid-transfer protein in intracellular lipid metabolism. SCP2 itself – a 13 kDa protein sharing the same domain – is known to bind cholesterol and various lipids with high affinity and facilitate their movement between membranes or organelles (pmc.ncbi.nlm.nih.gov). Indeed, SCP2 is often called a “nonspecific lipid transfer protein” and plays a major role in shuttling cholesterol, fatty acids, and other lipids inside cells (pmc.ncbi.nlm.nih.gov). Although SCP2D1 has not been directly studied, the conservation of the sterol-binding domain strongly suggests a similar role. In practical terms, the SCP2D1 protein likely binds hydrophobic lipid molecules in its cavity and transports them through the cytosol, delivering or exchanging these lipids at various membranes (e.g. endoplasmic reticulum, lipid droplets, mitochondria, or peroxisomes). Such transfer is crucial for processes like lipid trafficking, membrane biogenesis, and metabolic channeling of lipids.

Substrate specificity: Given its homology, SCP2D1 is expected to bind a broad range of lipid substrates. The classic SCP2 binds cholesterol as well as long-chain fatty acids and their CoA esters, showing a rather non-selective affinity for hydrophobic compounds (pubmed.ncbi.nlm.nih.gov). It is reasonable to infer that SCP2D1 can similarly accommodate cholesterol, sterol intermediates, long-chain fatty acyl-CoA, or bile acid precursors in its binding pocket. The large, flexible cavity of the SCP2 domain can adapt to different hydrophobic ligand shapes (pubmed.ncbi.nlm.nih.gov), which means SCP2D1 is not limited to a single lipid but likely acts on multiple lipid types (hence “non-specific” carrier). That said, the in vivo primary ligand is unknown – it might preferentially bind a particular class of lipids depending on where and when it’s expressed. No enzymatic activity (e.g. no catalytic conversion) is associated with SCP2D1; any effects on metabolism are indirect, by transporting substrates to the right location for other enzymes.

Molecular function evidence: Direct experimental evidence for SCP2D1’s function is still lacking. There are currently no biochemical assays or structural studies published specifically on human SCP2D1. All functional assertions are therefore inferred from homology (noted in databases as IEA: Inferred from Electronic Annotation). For example, the Alliance of Genome Resources and other genome annotation projects predict SCP2D1 to have lipid-binding activity and a role in lipid metabolic process, based on the conserved SCP2 domain (www.scbt.com) (pmc.ncbi.nlm.nih.gov). Santa Cruz Biotechnology’s data sheet echoes that “proteins that carry the SCP2 domain are implicated in the intracellular transport of lipids… crucial for lipid synthesis, breakdown, and conversion” (www.scbt.com). Until targeted studies are done, SCP2D1 remains functionally putative, with its biochemical role modeled on the known behavior of SCP2/SCPx family proteins.

Cellular Localization and Expression Pattern

Subcellular localization: SCP2D1 is an intracellular protein, predicted to reside in the cytosol. Unlike some SCP2-domain proteins, it does not appear to contain any organelle-targeting signal peptide. In particular, it lacks a canonical peroxisomal targeting sequence (PTS1 or PTS2) – for example, the prototypical human SCP2 has a C-terminal “AKL” motif that directs it to peroxisomes , but SCP2D1’s sequence does not include a known PTS1 like SKL/AKL at the extreme C-terminus. Consistent with this, genome annotation consortia (Alliance/HGNC) “predicted [SCP2D1] to be active in the cytosol.” (www.genecards.org). The Human Protein Atlas similarly designates SCP2D1’s predicted location as intracellular (cytosolic) (www.proteinatlas.org). In other words, SCP2D1 is thought to function in the cytoplasmic compartment, shuttling lipids between membranes within the cell. It is not a membrane-spanning protein and has no transmembrane domains, so it likely diffuses freely in the cytoplasm. There is also no indication of secretion; SCP2D1 lacks a signal peptide for the secretory pathway, and HPA’s analysis does not list it in the secretome.

One important comparison is with its paralog SCP2: the SCP2/SCPx gene produces a peroxisomal protein that, upon proteolytic processing, yields a small 13 kDa SCP2 which can also function in the cytosol (some SCP2 may distribute between cytosol and peroxisome) (pmc.ncbi.nlm.nih.gov). In contrast, SCP2D1 is a standalone 156-aa protein with presumably cytosolic distribution. The absence of a peroxisomal targeting motif suggests SCP2D1 might not enter peroxisomes at all, focusing its action in the cytosol or other organelles accessible without a targeting signal (potentially the endoplasmic reticulum or outer mitochondrial membrane surfaces). This difference raises the possibility that SCP2D1 could complement or extend the lipid-transfer roles of SCP2 in cellular regions outside peroxisomes.

Tissue expression: Intriguingly, SCP2D1 shows a very restricted expression profile. According to human transcriptomic data, it is strongly biased toward the testes. The Genotype-Tissue Expression (GTEx) project and Human Protein Atlas classify SCP2D1 as “tissue enriched in Testis.” (www.proteinatlas.org). GTEx reports dramatically higher mRNA levels in adult testis – on the order of ~53-fold above the average in other tissues (www.genecards.org). In fact, testis is often the only normal tissue where SCP2D1 transcripts are robustly detected. For example, GeneCards/GTEx data indicate SCP2D1 is overexpressed in testis (≈52.8×) relative to the next highest tissue (www.genecards.org). Conversely, in most other human tissues the mRNA is either extremely low or absent. The Protein Atlas RNA dataset likewise notes SCP2D1 is “not detected” in the majority of tissues and cell lines outside of the testis (www.proteinatlas.org).

This testis-centric expression suggests that SCP2D1 may fulfill a specialized role in male reproductive biology. The testes (particularly the seminiferous tubules) are known to have many unique or stage-specific proteins, often related to germ cell development or steroid hormone biosynthesis. SCP2D1’s high expression in testis hints at two broad possibilities: (1) it could be involved in spermatogenesis, e.g. providing or redistributing lipids needed for spermatid maturation and membrane remodeling, or (2) it might play a role in steroidogenesis within the testis (testosterone production by Leydig cells requires coordinated cholesterol transport). It is noteworthy that sterol carrier protein-2 (SCP2) itself has been implicated in cholesterol transfer for testosterone synthesis in Leydig cells (pubmed.ncbi.nlm.nih.gov). By analogy, SCP2D1 might assist in shuttling cholesterol to mitochondria where the first step of steroid hormone synthesis occurs, or generally maintain lipid homeostasis in the testicular environment. However, these roles for SCP2D1 are speculative – no direct experiments have yet linked SCP2D1 to sperm development or hormone production. Its expression in testis simply flags it as a candidate for such functions.

Outside the testis, SCP2D1 expression is very low, but some data (e.g. from animal models or broad RNA-seq surveys) suggest a few other sites might express it at minor levels. For instance, an expression atlas in pig reported SCP2D1 in testis and “2 other tissues” in that species (www.bgee.org), though the specific other tissues were not highlighted (possibly adrenal gland or liver, which are lipid-metabolic organs, but the expression there is much lower than in testis). In humans, if any extra-testicular expression exists, it might be in adrenal cortex or liver at trace levels, given those organs’ roles in sterol metabolism. Nonetheless, currently testis is the only tissue with significant SCP2D1 expression in humans (www.proteinatlas.org), making SCP2D1 akin to a “testis-enriched” or germ cell-associated protein. This pattern also classifies it as a potential cancer/testis antigen (since genes restricted to testes can sometimes be aberrantly expressed in cancers). However, cancer transcriptome data (TCGA) show SCP2D1 is not detected in common tumors (www.proteinatlas.org), and it has not been reported as a cancer/testis antigen in oncology literature. The Protein Atlas confirms SCP2D1 is not prognostic in cancers and has no appreciable expression in surveyed tumor samples (www.proteinatlas.org) (www.proteinatlas.org).

Protein-level evidence: It’s worth noting that as of now, SCP2D1 protein has only been evidenced at the transcript level. Large-scale proteomic studies have not detected it, likely due to its low abundance or limited expression domain (www.proteinatlas.org). The HPA assigns an “Evidence at transcript level” tag, meaning there is no direct protein identification by mass-spec or antibody-based methods yet. Commercial antibodies against SCP2D1 are available, and researchers have cloned the ORF in expression vectors (www.thermofisher.com), but we have no public reports of Western blots or immunohistochemistry confirming the protein in tissues. The lack of protein confirmation, combined with the testis-restricted expression, suggests SCP2D1 could be a low-copy number protein or one requiring very specific conditions to be expressed. This also underscores the need for further experimental validation of its expression and subcellular localization (for example, immunofluorescence in testis sections could show whether it is in germ cells, Sertoli cells, or Leydig cells).

Biological Processes and Pathway Involvement

Lipid metabolism and transport: By all indications, SCP2D1 functions in the context of intracellular lipid metabolism. Proteins containing SCP2 domains have established roles in processes such as fatty acid β-oxidation, cholesterol homeostasis, and lipid trafficking between organelles (pmc.ncbi.nlm.nih.gov). SCP2D1’s closest homolog, SCP2/SCPx, is deeply involved in peroxisomal β-oxidation of long-chain fatty acids and the inter-organelle movement of cholesterol (e.g., aiding cholesterol transfer to mitochondria for steroidogenesis or to peroxisomes for bile acid synthesis) (pmc.ncbi.nlm.nih.gov). While SCP2D1 itself is not known to reside in peroxisomes, it may participate in parallel pathways outside peroxisomes, possibly facilitating cholesterol transfer to other organelles or distribution of fatty acids in the cytosol. For example, one could envisage SCP2D1 helping deliver cholesterol from the plasma membrane or lipid droplets to the mitochondrial outer membrane – a critical step in steroid hormone production in steroidogenic cells. This hypothesis aligns with its testicular expression (since Leydig cells require efficient cholesterol transport for testosterone synthesis). It also might contribute to germ cell lipid needs; spermatids undergo dramatic membrane remodeling and produce specialized lipids (like plasmalogens) – a lipid shuttle protein could assist in those processes.

Pathway affiliations: No specific curated pathway (e.g. in KEGG or Reactome) has been assigned to SCP2D1 as of 2024, largely due to the scant functional data. However, based on its presumed activity, SCP2D1 touches on pathways such as:

Protein interaction networks: Although direct protein partners of SCP2D1 are unconfirmed, computational interaction networks like STRING provide some clues. STRING’s analysis (which integrates co-expression, text mining, and homology data) predicts that SCP2D1 is functionally associated with a set of proteins involved in lipid metabolism and membrane dynamics. For instance, SCP2D1 shows predicted links to:

It must be emphasized that these interactions are predicted with moderate confidence and have not been validated in vivo (string-db.org) (string-db.org). They do, however, paint a consistent picture: SCP2D1 is likely functionally embedded in lipid metabolic networks, working alongside enzymes of fatty acid and cholesterol metabolism.

Biological process GO terms (inferred): As of the latest RefSeq/GO annotations, SCP2D1 is expected to contribute to “lipid transport” and “lipid metabolic process”, and to localize to the “cytosol”, based on electronic annotation (IEA) from its sequence features. These GO terms echo what has been described: involvement in moving lipids around the cell (transport) and participation in the broader context of lipid metabolism. Experimental validation would be needed to confirm these GO annotations.

Current Understanding and Research Status

Given the paucity of direct studies, our understanding of SCP2D1 is still preliminary and based on inference. Key points of current understanding include:

Expert opinions and analysis: Reviews on lipid transport proteins have underscored the importance of SCP2 in intracellular cholesterol trafficking and fatty acid metabolism (pmc.ncbi.nlm.nih.gov). Experts note that SCP2’s lipid-binding ability is crucial for processes like peroxisomal β-oxidation and even link defects in SCP2 to complex disorders of lipid balance (e.g., Zellweger syndrome, a peroxisomal biogenesis disorder that affects lipid trafficking) (pmc.ncbi.nlm.nih.gov). By extension, scientists consider that any protein harboring an SCP2 domain (such as SCP2D1) may play complementary roles in these lipid processes. In a 2016 analysis of cholesterol transport in Leydig cells, researchers highlighted SCP2 as a key facilitator of cholesterol movement inside the cell (pmc.ncbi.nlm.nih.gov) – a role that could theoretically be shared or modulated by SCP2D1 in testicular cells. However, no direct commentary from experts on SCP2D1 specifically is available, reflecting its status as an unstudied gene. The consensus among functional genomics resources (GeneCards, HGNC, etc.) is that SCP2D1 is “uncharacterized” and its function “has yet to be elucidated.” (www.scbt.com). This places SCP2D1 in a category of genes that are recognized at the sequence level and predicted to have important domains, but await detailed functional analysis.

Data from recent studies (2023–2024): In the absence of dedicated studies on SCP2D1, recent data come mainly from high-throughput efforts and database updates. For instance, the Human Protein Atlas (2023) confirms the testis-specific RNA expression and notes the lack of protein-level evidence for SCP2D1 (www.proteinatlas.org) (www.proteinatlas.org). The Alliance of Genome Resources (2024 update) continues to annotate SCP2D1 as a cytosolic protein with SCP2 domain, without new functional data (www.genecards.org). No new mutations or disease associations have been reported in the latest (2023) literature – SCP2D1 is not present in GWAS hits or clinical variant databases with any significance at this time (variants have been identified in sequencing projects, but classified as of uncertain significance and not linked to disease) (www.genecards.org) (www.genecards.org).

One tangentially relevant update is the refinement of the locus for Posterior Polymorphous Corneal Dystrophy 1 (PPCD1), an inherited eye disorder linked to chromosome 20. SCP2D1 lies in the 20p11.23 region, which was historically marked as PPCD1. However, despite initial exploration, no evidence has implicated SCP2D1 in that disease – other genes in the region or non-coding elements are now suspected, and SCP2D1 remains simply a neighbor in the locus (www.genecards.org). Similarly, SCP2D1’s name “HSD22” (a deprecated alias) once caused confusion with 17β-hydroxysteroid dehydrogenase type IV (HSD17B4), the gene for D-bifunctional protein, because HSD17B4 deficiency (a peroxisomal disorder) involves a sterol-binding domain issue. It’s now clear HSD17B4 is a different entity; SCP2D1’s only connection is that HSD17B4’s enzyme contains a sterol-carrier domain, loosely paralleling SCP2D1’s domain (www.genecards.org). The mention of D-bifunctional protein deficiency in older databases likely reflects this shared domain concept rather than a direct role of SCP2D1 in the disease. In short, no direct pathology has been tied to SCP2D1 as of 2024, reinforcing that its function might be somewhat redundant or subtler, possibly compensated by other lipid carriers in most tissues.

Conclusion and Future Directions

SCP2D1 encodes a sterol-binding domain protein believed to act as an intracellular lipid carrier. It shares the key functional motif of sterol carrier protein-2, implying that it can bind cholesterol and fatty acids and facilitate their intracellular trafficking (pubmed.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). The protein is predicted to reside in the cytosol and is expressed predominantly in the testis, suggesting a specialized role in testicular lipid processes or fertility-related metabolism (www.genecards.org) (www.genecards.org). While it likely contributes to lipid homeostasis, the precise biochemical pathway (be it aiding steroid hormone biosynthesis, sperm membrane formation, or another lipid-dependent process) remains to be determined.

To date, experimental evidence for SCP2D1’s function is lacking, and it is considered an uncharacterized protein in curated databases (www.scbt.com). Its functional annotation relies on homology and indirect network predictions. Authoritative sources emphasize the importance of the SCP2-like domain in lipid transport, lending support to the inferred role of SCP2D1 in similar pathways (pmc.ncbi.nlm.nih.gov). However, SCP2D1’s exact substrate specificity, interacting partners, and physiological role are open questions.

Future research – such as targeted knockdown/knockout studies in model organisms or in vitro lipid-binding assays with recombinant SCP2D1 – will be crucial to validate its function. Given its testis enrichment, a mouse Scp2d1 knockout could be examined for effects on male fertility, steroid levels, or testis histology. Biochemical assays could test binding affinity of SCP2D1 for cholesterol versus other lipids, to see if it has a preference (for example, some carriers preferentially bind cholesterol over phospholipids, etc.). Additionally, microscopy of testis tissue using specific antibodies (once available and validated) could localize SCP2D1 to particular cell types (germ cells or Leydig cells) and subcellular structures, providing clues to its role (e.g., co-localization with mitochondria would hint at steroidogenesis involvement).

In summary, SCP2D1 appears to be a cytosolic lipid transfer protein with a sterol-binding domain, paralleling the function of sterol carrier protein-2. It likely safeguards or shuttles vital lipid molecules within cells, with a unique importance in the testis. Its precise function and pathway context are still under investigation, making it an interesting target for future functional genomics and biochemical studies to fully elucidate its role in human biology (www.scbt.com).

References:

(All citations above correspond to the referenced lines from source materials, supporting the statements made.)

Citations

  1. AnnotationURLCitation(end_index=425, start_index=324, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=3%20%7D%20,2')
  2. AnnotationURLCitation(end_index=575, start_index=426, title='SCP2D1激活剂 | SCBT - Santa Cruz Biotechnology', type='url_citation', url='https://www.scbt.com/browse/scp2d1-activators#:~:text=SCP2D1%2C%20or%20Sterol%20Carrier%20Protein,have%20yet%20to%20be%20elucidated')
  3. AnnotationURLCitation(end_index=1062, start_index=912, title='SCP2D1激活剂 | SCBT - Santa Cruz Biotechnology', type='url_citation', url='https://www.scbt.com/browse/scp2d1-activators#:~:text=When%20proteins%20are%20not%20well,are%20implicated%20in%20the%20intracellular')
  4. AnnotationURLCitation(end_index=1374, start_index=1225, title='SCP2D1激活剂 | SCBT - Santa Cruz Biotechnology', type='url_citation', url='https://www.scbt.com/browse/scp2d1-activators#:~:text=SCP2D1%2C%20or%20Sterol%20Carrier%20Protein,have%20yet%20to%20be%20elucidated')
  5. AnnotationURLCitation(end_index=1679, start_index=1530, title='SCP2D1激活剂 | SCBT - Santa Cruz Biotechnology', type='url_citation', url='https://www.scbt.com/browse/scp2d1-activators#:~:text=SCP2D1%2C%20or%20Sterol%20Carrier%20Protein,have%20yet%20to%20be%20elucidated')
  6. AnnotationURLCitation(end_index=1813, start_index=1680, title='SCP2D1激活剂 | SCBT - Santa Cruz Biotechnology', type='url_citation', url='https://www.scbt.com/browse/scp2d1-activators#:~:text=sequencing%20data,are%20implicated%20in%20the%20intracellular')
  7. AnnotationURLCitation(end_index=2371, start_index=2211, title='The crystal structure of sterol carrier protein 2 from Yarrowia lipolytica and the evolutionary conservation of a large, non-specific lipid-binding cavity - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/24241823/#:~:text=that%20the%20cavity%20of%20the,cellular%20contexts%20and%20metabolic%20conditions')
  8. AnnotationURLCitation(end_index=2742, start_index=2582, title='The crystal structure of sterol carrier protein 2 from Yarrowia lipolytica and the evolutionary conservation of a large, non-specific lipid-binding cavity - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/24241823/#:~:text=that%20the%20cavity%20of%20the,cellular%20contexts%20and%20metabolic%20conditions')
  9. AnnotationURLCitation(end_index=3627, start_index=3476, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
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  17. AnnotationURLCitation(end_index=8193, start_index=8054, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=Gene%20description,Not%20detected%20Not%20detected')
  18. AnnotationURLCitation(end_index=9014, start_index=8863, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
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  20. AnnotationURLCitation(end_index=10289, start_index=10122, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=mRNA%20differential%20expression%20in%20normal,to%20GTEx%20for%20SCP2D1%20Gene')
  21. AnnotationURLCitation(end_index=10677, start_index=10510, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=mRNA%20differential%20expression%20in%20normal,to%20GTEx%20for%20SCP2D1%20Gene')
  22. AnnotationURLCitation(end_index=11063, start_index=10897, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=RNA%20category,transcript%20level%20IMMUNOHISTOCHEMISTRY%20DATA%20RELIABILITY')
  23. AnnotationURLCitation(end_index=12040, start_index=11883, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/26901662/#:~:text=Skip%20to%20main%20page%20content,in%20intracellular%20lipid%20transport%20and')
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  25. AnnotationURLCitation(end_index=13516, start_index=13350, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=RNA%20category,transcript%20level%20IMMUNOHISTOCHEMISTRY%20DATA%20RELIABILITY')
  26. AnnotationURLCitation(end_index=14013, start_index=13844, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=Detected%20in%20single%20Cell%20line,i%7D%20Pending%20cancer%20tissue%20analysis')
  27. AnnotationURLCitation(end_index=14388, start_index=14222, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=RNA%20category,transcript%20level%20IMMUNOHISTOCHEMISTRY%20DATA%20RELIABILITY')
  28. AnnotationURLCitation(end_index=14558, start_index=14389, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=SCP2D1%20is%20not%20prognostic%20RNA,i%7D%20Pending%20cancer%20tissue%20analysis')
  29. AnnotationURLCitation(end_index=14980, start_index=14804, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=Not%20detected%20TCGA%20,transcript%20level%20IMMUNOHISTOCHEMISTRY%20DATA%20RELIABILITY')
  30. AnnotationURLCitation(end_index=15417, start_index=15241, title='C20orf79 Monoclonal Antibody (3C11) (H00140856-M01)', type='url_citation', url='https://www.thermofisher.com/antibody/product/C20orf79-Antibody-clone-3C11-Monoclonal/H00140856-M01#:~:text=C20orf79%20Monoclonal%20Antibody%20,produc')
  31. AnnotationURLCitation(end_index=16457, start_index=16306, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
  32. AnnotationURLCitation(end_index=16881, start_index=16730, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
  33. AnnotationURLCitation(end_index=18944, start_index=18787, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/26901662/#:~:text=Skip%20to%20main%20page%20content,in%20intracellular%20lipid%20transport%20and')
  34. AnnotationURLCitation(end_index=19938, start_index=19796, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=and%20morphology,Mitochondrial%20trifunctional%20enzyme%20is%20a')
  35. AnnotationURLCitation(end_index=20030, start_index=19939, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=,CoA.%20Using')
  36. AnnotationURLCitation(end_index=20426, start_index=20347, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=,')
  37. AnnotationURLCitation(end_index=20511, start_index=20427, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=,0.525')
  38. AnnotationURLCitation(end_index=20790, start_index=20664, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=,mitochondrial%3B%20Able%20to%20isomerize%20both')
  39. AnnotationURLCitation(end_index=20947, start_index=20868, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=,')
  40. AnnotationURLCitation(end_index=21242, start_index=21116, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=,mitochondrial%3B%20Able%20to%20isomerize%20both')
  41. AnnotationURLCitation(end_index=21664, start_index=21542, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=,the%20regulation%20of%20Golgi%20maintenance')
  42. AnnotationURLCitation(end_index=22017, start_index=21933, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=,0.544')
  43. AnnotationURLCitation(end_index=22265, start_index=22153, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=3,it%20can%20also%20catalyze%20the')
  44. AnnotationURLCitation(end_index=22387, start_index=22266, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=by%20leptin%20in%20the%20hypothalamus,0.525')
  45. AnnotationURLCitation(end_index=22834, start_index=22724, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=Your%20Input%3A%20%20,In%20vitro')
  46. AnnotationURLCitation(end_index=22958, start_index=22835, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=Predicted%20Functional%20Partners%3A%20,rapid')
  47. AnnotationURLCitation(end_index=24232, start_index=24072, title='The crystal structure of sterol carrier protein 2 from Yarrowia lipolytica and the evolutionary conservation of a large, non-specific lipid-binding cavity - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/24241823/#:~:text=that%20the%20cavity%20of%20the,cellular%20contexts%20and%20metabolic%20conditions')
  48. AnnotationURLCitation(end_index=24384, start_index=24233, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
  49. AnnotationURLCitation(end_index=24766, start_index=24636, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=NCBI%20Gene%20Summary%20for%20SCP2D1,Gene')
  50. AnnotationURLCitation(end_index=25410, start_index=25243, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=mRNA%20differential%20expression%20in%20normal,to%20GTEx%20for%20SCP2D1%20Gene')
  51. AnnotationURLCitation(end_index=26322, start_index=26171, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
  52. AnnotationURLCitation(end_index=26737, start_index=26586, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
  53. AnnotationURLCitation(end_index=27189, start_index=27038, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
  54. AnnotationURLCitation(end_index=27716, start_index=27567, title='SCP2D1激活剂 | SCBT - Santa Cruz Biotechnology', type='url_citation', url='https://www.scbt.com/browse/scp2d1-activators#:~:text=SCP2D1%2C%20or%20Sterol%20Carrier%20Protein,have%20yet%20to%20be%20elucidated')
  55. AnnotationURLCitation(end_index=28359, start_index=28193, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=RNA%20category,transcript%20level%20IMMUNOHISTOCHEMISTRY%20DATA%20RELIABILITY')
  56. AnnotationURLCitation(end_index=28536, start_index=28360, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=Not%20detected%20TCGA%20,transcript%20level%20IMMUNOHISTOCHEMISTRY%20DATA%20RELIABILITY')
  57. AnnotationURLCitation(end_index=28813, start_index=28683, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=NCBI%20Gene%20Summary%20for%20SCP2D1,Gene')
  58. AnnotationURLCitation(end_index=29344, start_index=29137, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=%7C%2018%2C813%2C878%28%2B%29%20%20%7C%20NM_178483.3%28SCP2D1%29%3Ac.63G,Uncertain%20significance%3A%20not%20specified')
  59. AnnotationURLCitation(end_index=29553, start_index=29345, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=%7C%2018%2C813%2C944%28%2B%29%20%20%7C%20NM_178483.3%28SCP2D1%29%3Ac.129G,Uncertain%20significance%3A%20not%20specified')
  60. AnnotationURLCitation(end_index=30166, start_index=30020, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=Corneal%20Dystrophy%2C%20Posterior%20Polymorphous%2C%201,')
  61. AnnotationURLCitation(end_index=30731, start_index=30602, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=SCP2D1%20Gene%20,Variants%20for%20SCP2D1')
  62. AnnotationURLCitation(end_index=31564, start_index=31404, title='The crystal structure of sterol carrier protein 2 from Yarrowia lipolytica and the evolutionary conservation of a large, non-specific lipid-binding cavity - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/24241823/#:~:text=that%20the%20cavity%20of%20the,cellular%20contexts%20and%20metabolic%20conditions')
  63. AnnotationURLCitation(end_index=31716, start_index=31565, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
  64. AnnotationURLCitation(end_index=32040, start_index=31910, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=NCBI%20Gene%20Summary%20for%20SCP2D1,Gene')
  65. AnnotationURLCitation(end_index=32208, start_index=32041, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=mRNA%20differential%20expression%20in%20normal,to%20GTEx%20for%20SCP2D1%20Gene')
  66. AnnotationURLCitation(end_index=32719, start_index=32570, title='SCP2D1激活剂 | SCBT - Santa Cruz Biotechnology', type='url_citation', url='https://www.scbt.com/browse/scp2d1-activators#:~:text=SCP2D1%2C%20or%20Sterol%20Carrier%20Protein,have%20yet%20to%20be%20elucidated')
  67. AnnotationURLCitation(end_index=33109, start_index=32958, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
  68. AnnotationURLCitation(end_index=34715, start_index=34566, title='SCP2D1激活剂 | SCBT - Santa Cruz Biotechnology', type='url_citation', url='https://www.scbt.com/browse/scp2d1-activators#:~:text=SCP2D1%2C%20or%20Sterol%20Carrier%20Protein,have%20yet%20to%20be%20elucidated')
  69. AnnotationURLCitation(end_index=34996, start_index=34866, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=NCBI%20Gene%20Summary%20for%20SCP2D1,Gene')
  70. AnnotationURLCitation(end_index=35309, start_index=35160, title='SCP2D1激活剂 | SCBT - Santa Cruz Biotechnology', type='url_citation', url='https://www.scbt.com/browse/scp2d1-activators#:~:text=SCP2D1%2C%20or%20Sterol%20Carrier%20Protein,have%20yet%20to%20be%20elucidated')
  71. AnnotationURLCitation(end_index=35449, start_index=35310, title='SCP2D1激活剂 | SCBT - Santa Cruz Biotechnology', type='url_citation', url='https://www.scbt.com/browse/scp2d1-activators#:~:text=sequencing%20data,conversion%20into%20other%20biologically%20active')
  72. AnnotationURLCitation(end_index=35859, start_index=35699, title='The crystal structure of sterol carrier protein 2 from Yarrowia lipolytica and the evolutionary conservation of a large, non-specific lipid-binding cavity - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/24241823/#:~:text=that%20the%20cavity%20of%20the,cellular%20contexts%20and%20metabolic%20conditions')
  73. AnnotationURLCitation(end_index=36267, start_index=36116, title='Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4762939/#:~:text=is%20thought%20to%20play%20a,SCP2%20proteins%2C%20both%20of%20which')
  74. AnnotationURLCitation(end_index=36587, start_index=36448, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=Gene%20description,Not%20detected%20Not%20detected')
  75. AnnotationURLCitation(end_index=36754, start_index=36588, title='Expression of SCP2D1 in cancer - Summary - The Human Protein Atlas', type='url_citation', url='https://www.proteinatlas.org/ENSG00000132631/pathology#:~:text=RNA%20category,transcript%20level%20IMMUNOHISTOCHEMISTRY%20DATA%20RELIABILITY')
  76. AnnotationURLCitation(end_index=37062, start_index=36895, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=mRNA%20differential%20expression%20in%20normal,to%20GTEx%20for%20SCP2D1%20Gene')
  77. AnnotationURLCitation(end_index=37382, start_index=37240, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=and%20morphology,Mitochondrial%20trifunctional%20enzyme%20is%20a')
  78. AnnotationURLCitation(end_index=37509, start_index=37383, title='SCP2D1 protein (human) - STRING interaction network', type='url_citation', url='https://string-db.org/network/9606.ENSP00000366645#:~:text=,mitochondrial%3B%20Able%20to%20isomerize%20both')
  79. AnnotationURLCitation(end_index=37803, start_index=37676, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=SCP2D1%20,of%20this%20gene%20is%20SCP2')
  80. AnnotationURLCitation(end_index=37966, start_index=37804, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=match%20at%20L493%20No%20data,HOMER%20Transcription%20for%20SCP2D1%20Gene')
  81. AnnotationURLCitation(end_index=38313, start_index=38167, title='SCP2D1 Gene - GeneCards | SCP2D Protein | SCP2D Antibody', type='url_citation', url='https://www.genecards.org/cgi-bin/carddisp.pl?gene=SCP2D1#:~:text=Corneal%20Dystrophy%2C%20Posterior%20Polymorphous%2C%201,')