Overview of RAB15 (Ras-related Protein Rab-15) in Human Cells OpenAI o3-deep-research-2025-06-26 87 citations 2025-12-27T21:21:46.149401

Overview of RAB15 (Ras-related Protein Rab-15) in Human Cells

RAB15 is a member of the small GTPase Rab family, which belongs to the Ras superfamily of regulatory proteins. Like other Rab GTPases, RAB15 is a molecular switch that cycles between an inactive GDP-bound state and an active GTP-bound state, thereby controlling various steps of intracellular membrane trafficking (www.reactome.org). In its GTP-bound form, RAB15 can recruit specific effector proteins to membranes, directing processes such as vesicle formation, movement along cytoskeletal tracks, and membrane tethering/fusion (www.reactome.org). This GTPase activity (EC 3.6.5.2) allows RAB15 to hydrolyze GTP and switch to the GDP-bound state, a cycle tightly regulated by accessory factors: guanine nucleotide exchange factors (GEFs) that activate Rab15 by promoting GDP–GTP exchange, GTPase-activating proteins (GAPs) that accelerate GTP hydrolysis, and GDP dissociation inhibitors (GDIs) that sequester the inactive Rab in the cytosol (www.reactome.org). RAB15 is a ~212 amino acid protein with a conserved P-loop NTP-binding domain characteristic of Ras-like GTPases. It undergoes post-translational prenylation at C-terminal cysteine residues (a hallmark of Rab proteins) which anchors it to cellular membranes (pmc.ncbi.nlm.nih.gov).

Gene and Expression: The RAB15 gene (UniProt P59190) is expressed in Homo sapiens and was first noted as a brain-enriched Rab protein. Early studies in rat identified Rab15 as a low molecular weight GTP-binding protein predominantly expressed in the brain (www.nature.com). Consistently, human RAB15 shows high expression in neural tissues, suggesting specialized roles in neurons. Notably, alternative splicing of the RAB15 transcript produces distinct isoforms. In neuroblastoma cells, two isoforms have been described: a 212-amino acid form termed Rab15CN, which includes all 7 exons and is primarily expressed in brain, and a slightly shorter isoform Rab15AN (208 amino acids) generated by skipping exon 4, predominantly expressed in testis (pubmed.ncbi.nlm.nih.gov). Intriguingly, retinoic acid-induced differentiation of neuroblastoma cells specifically upregulates the Rab15CN isoform and favors differentiation in cells expressing Rab15CN over those expressing Rab15AN (pubmed.ncbi.nlm.nih.gov). These findings suggest that Rab15CN may be the functionally relevant form in neurons, and RAB15 expression correlates with neuronal differentiation status (pubmed.ncbi.nlm.nih.gov). Outside the brain, RAB15 is expressed at lower levels in various tissues, and large-scale RNA analyses indicate it is not among the most ubiquitously expressed Rabs (which are Rab5, Rab7, etc.), underscoring a more cell-type specific role.

Cellular Localization: Within the cell, RAB15 is primarily associated with endosomal membranes. It localizes to early/sorting endosomes and the perinuclear recycling endosome compartment (pmc.ncbi.nlm.nih.gov) (www.nature.com). In cultured cells (e.g. CHO and HeLa cells), epitope-tagged Rab15 co-localizes with markers of early endosomes (such as Rab5 and early endosome antigen 1, EEA1) and with Rab4 on sorting endosomes, as well as with Rab11 on the endocytic recycling compartment (ERC) (www.nature.com). This distribution implies that Rab15 participates in endocytic sorting and in recycling of internalized cargo back to the plasma membrane. RAB15 has also been detected in the perinuclear region of the cytoplasm, consistent with localization to the ERC, which often surrounds the microtubule-organizing center (www.ncbi.nlm.nih.gov). Some data even suggest RAB15 might localize to primary cilia or related membranes (www.ncbi.nlm.nih.gov), although its function in ciliary trafficking is not well characterized. In neurons, given the high expression in brain, Rab15 is believed to be present on neuronal endosomal compartments and possibly synaptic vesicle recycling pools. Indeed, by sequence homology, it has been proposed that Rab15 may act in concert with Rab3A (a synaptic vesicle-associated Rab) to regulate membrane flow at nerve terminals (www.reactome.org), although direct experimental evidence for Rab15’s role in synapses is limited.

Biological Function – Role in Endocytosis and Recycling: RAB15 is a key regulator of the endocytic recycling pathway, which returns internalized receptors and membrane components back to the cell surface. Classic studies by Zuk and Elferink were among the first to elucidate Rab15’s function in endosomes. In Chinese hamster ovary (CHO) cells, overexpression of wild-type or GTPase-deficient (constitutively active) Rab15 was found to inhibit early endocytic uptake of cargo. Specifically, GTP-bound Rab15 (e.g. the Q67L mutant that locks Rab15 in an active state) reduced both fluid-phase and receptor-mediated endocytosis without altering the overall recycling rate of transferrin receptors from early endosomes (pubmed.ncbi.nlm.nih.gov). This suggested that active Rab15 puts a “brake” on the initial phase of endosome formation or fusion. Indeed, Rab15 activity was shown to slow the homotypic fusion of early endosomes, thereby delaying the maturation or enlargement of early endocytic vesicles (pubmed.ncbi.nlm.nih.gov). Conversely, the GDP-bound (inactive) form of Rab15 had the opposite effect. Cells expressing dominant-negative Rab15 mutants (such as T22N, which mimics the GDP-bound state, or N121I, a nucleotide-free mutant) showed enhanced endocytic uptake and accelerated fusion of early endosomes (pubmed.ncbi.nlm.nih.gov). In other words, inactivating Rab15 releases the brake, allowing endocytosis to proceed more rapidly. Notably, the inactive Rab15 mutants also caused changes in the recycling pathway – they differentially affected the transit of cargo through sorting vs. recycling endosomes, in some cases impairing the normal return of receptors to the surface (pubmed.ncbi.nlm.nih.gov). These combined data led researchers to conclude that Rab15 antagonizes the function of Rab5, the master regulator of early endosome fusion. Rab5 normally accelerates vesicle fusion and cargo sorting in the early endocytic pathway, and Rab15 appears to counteract this, preventing excessive or premature fusion (pubmed.ncbi.nlm.nih.gov). Supporting this model, constitutively active Rab15 was shown to attenuate Rab5-driven endosome fusion and endocytosis, whereas a GDP-locked Rab15 enhanced the effects of active Rab5 (pubmed.ncbi.nlm.nih.gov). Thus, Rab15 serves as a modulator of early endosomal dynamics, ensuring a balanced rate of cargo internalization and progression through the endosomal system.

Importantly, RAB15’s role is not limited to the early endosome; it also functions at later stages of the recycling route. The endocytic recycling compartment (ERC), marked by Rab11, is the station for “slow” recycling whereby internalized receptors can be stored and later returned to the membrane. Rab15 is one of the few Rabs that localize to both sorting endosomes and the ERC, suggesting it helps coordinate traffic between these connected stages (www.nature.com). In fact, Rab15 has been implicated in both the “fast” recycling route (direct return from sorting endosomes, which typically involves Rab4/Rab5) and the “slow” recycling route (via Rab11-positive ERC) (pmc.ncbi.nlm.nih.gov). A 2011 review noted that after endocytosis, some receptors recycle rapidly with Rab4, Rab14, and Rab15 on sorting endosomes, while others take a slower route through Rab11/Rab15 compartments (pmc.ncbi.nlm.nih.gov). This dual presence indicates RAB15 might regulate the decision or transition between these two recycling pathways.

Rab15 Effector – REP15 and Mechanistic Insights: Like other Rab GTPases, Rab15 exerts its effects by recruiting effector proteins that execute trafficking steps. A major advance in understanding Rab15 came with the discovery of a specific effector, named Rab15 Effector Protein (REP15), by Strick and Elferink (2005). REP15 was identified via yeast two-hybrid and co-immunoprecipitation as a protein that binds directly to GTP-bound Rab15 (pmc.ncbi.nlm.nih.gov). Notably, REP15 localizes selectively to the endocytic recycling compartment: it co-localizes with Rab15 and Rab11 in the perinuclear ERC, but is absent from early sorting endosomes (pmc.ncbi.nlm.nih.gov). In other words, REP15 associates with Rab15 only on the recycling endosome subpopulation, not on the initial early endosomes. Mechanistically, REP15 appears to mediate the “slow” recycling of receptors from the ERC to the plasma membrane. When REP15 levels are manipulated, there are specific effects on receptor trafficking: overexpression or siRNA knockdown of REP15 both inhibit transferrin receptor recycling from the ERC, without affecting the initial internalization of transferrin or its rapid recycling from sorting endosomes (pmc.ncbi.nlm.nih.gov). This result indicates that REP15 is required for the efficient exit of cargo from the ERC (a slower phase of recycling), while Rab15 likely uses other effectors for earlier stages. The recruitment of REP15 by Rab15-GTP thus provides a molecular mechanism for how Rab15 controls the slow recycling pathway. It “gates” the release of receptors from the ERC, possibly by organizing vesicle budding or tethering events specific to that compartment (pmc.ncbi.nlm.nih.gov). Overall, Rab15 differentially regulates transferrin receptor trafficking through sorting endosomes vs. the ERC by engaging distinct effectors at each station (pmc.ncbi.nlm.nih.gov). The discovery of REP15 underscored that RAB15’s function is compartment-specific: the same Rab protein can have multiple roles depending on which effector it binds and where.

Beyond REP15, emerging evidence suggests Rab15 can interact with a broader network of effectors, some of which are shared with other Rabs. A recent study characterized Rep15’s structure and interactions and also noted that Rab15 binds a set of bMERB domain proteins (www.nature.com) (www.nature.com). These include MICAL1, MICAL3, MICAL-cL, EHBP1, and EHBP1L1 – factors known to link Rab GTPases to actin cytoskeleton remodeling and membrane tubulation (www.nature.com). Interestingly, MICAL and EHBP1 family members are typically effectors for Rab8/Rab10 involved in recycling and cytoskeletal dynamics (www.nature.com). The finding that Rab15 can also recruit these effectors suggests functional overlap or crosstalk between Rab15 and other Rabs in coordinating endosome-to-membrane transport. The exact functional significance of Rab15’s interaction with bMERB-domain effectors remains to be fully elucidated (www.nature.com). One hypothesis is that Rab15, perhaps in its sorting-endosome locale, might influence actin or membrane tubule formation to regulate sorting decisions (for example, determining which tubules go back to the surface vs. to the Golgi or remain endosomal). Further structural analysis in 2022 provided high-resolution insight into Rab15-effector binding: Rep15 was crystallized in complex with Rab3 isoforms, revealing a unique globular fold distinct from other known Rab effector complexes (www.nature.com). These structural studies confirmed that Rep15 binds Rab15 in a 1:1 stoichiometry with high affinity and clarified how Rep15 recognizes Rab15 versus other Rabs (www.nature.com). Interestingly, Rep15 turned out capable of binding not only Rab15 but also certain Rab3 paralogs and Rab34, though it does not bind Rab5 or Rab11 (pmc.ncbi.nlm.nih.gov) (www.nature.com). Mutational analysis pinpointed key amino acids that confer this specificity (www.nature.com). Such data expand our understanding of the Rab15 interactome and suggest that RAB15 might function in concert with other Rabs (Rab3, Rab34) in specific cell contexts, possibly linking endosomal recycling with secretory vesicle pools or lysosomal pathways.

Physiological and Pathway Context: The primary pathway regulated by Rab15 is the endocytic recycling pathway, which is crucial for maintaining cell surface homeostasis. For example, the transferrin receptor (TfR) – which mediates iron uptake – continuously cycles between the plasma membrane and endosomes. Rab15 helps control the rate and route of TfR recycling (pmc.ncbi.nlm.nih.gov). Under normal conditions, a portion of internalized TfR rapidly returns to the membrane directly from early endosomes (fast route), while another portion is delivered to the ERC and recycled more slowly (slow route). By engaging different effectors at early endosomes vs. the ERC, Rab15 can bias trafficking toward one route or modulate the timing. This ensures, for instance, that receptors are not recycled too quickly (which could lead to uncontrolled signaling or uptake) and that endosomes have adequate time for sorting. Rab15’s “brake” on early endosome fusion likely prevents excessive enlargement or premature transition to late endosomes, maintaining a proper sorting compartment for receptors (pubmed.ncbi.nlm.nih.gov). In cells where Rab15 is absent or inactive, Rab5-driven early fusion predominates, potentially accelerating cargo degradation or mis-sorting. Thus, Rab15 contributes to the fidelity of cargo recycling versus degradation.

There is also evidence that Rab15’s regulation of endosome dynamics has implications for other cellular pathways like autophagy and pathogen defense. Autophagy, particularly the maturation of autophagosomes into degradative autolysosomes, intersects with endocytic trafficking. Recent studies (2023–2024) indicate that Rab15 can act as a negative regulator of autophagy by restraining endosome maturation. Specifically, depletion of RAB15 was found to promote the maturation of early endosomes into late endosomes that fuse with lysosomes, thereby enhancing autophagic flux (pmc.ncbi.nlm.nih.gov). Conversely, when Rab15 is active, early endosomal compartments are prolonged and their fusion with lysosomes is inhibited, which tends to slow autophagic degradation of cargo (pmc.ncbi.nlm.nih.gov). This phenomenon has been observed in the context of intracellular bacterial infection. For example, the bacterium Ehrlichia chaffeensis hijacks the host cell’s endosomal system to create a protective niche (an Ehrlichia-containing vacuole, ECV). A 2024 study showed that Ehrlichia secretes an effector (Etf-3) that specifically upregulates host RAB15 expression, leading to increased Rab15 on the ECV membrane (www.mdpi.com) (www.mdpi.com). Rab15 enrichment on these vacuoles prevents their fusion with RAB7-positive late endosomes/lysosomes and at the same time induces an autophagy-like environment around the vacuole (www.mdpi.com) (www.mdpi.com). When RAB15 was silenced by siRNA in infected cells, the ECVs more readily acquired late endosomal markers (like RAB7 and mannose-6-phosphate receptor) and fused with lysosomes, resulting in clearance of the bacteria (www.mdpi.com) (www.mdpi.com). Moreover, Rab15 knockdown abolished the accumulation of LC3-II (an autophagosome marker) normally seen during infection (www.mdpi.com), indicating that Rab15 was required for the pro-autophagic response to infection. In sum, Rab15 helps the pathogen by keeping its vacuole in an “early” state and promoting autophagy initiation (perhaps to supply nutrients) without completion of degradation (pmc.ncbi.nlm.nih.gov) (www.mdpi.com). This is a striking example of how Rab15’s role in endosome maturation has broader consequences: it can be subverted by pathogens to evade destruction. The Ehrlichia study not only shed light on host-pathogen interaction but also reinforced that Rab15 is a critical node controlling the balance between recycling/sorting vs. degradation in the endolysosomal system (www.mdpi.com) (www.mdpi.com). These recent findings expand our understanding of Rab15’s function beyond “housekeeping” receptor recycling, showing it can influence autophagic flux and immune defense.

Current Developments and Applications: While RAB15 is not as extensively studied as some other Rab proteins, there is growing interest in its potential roles in health and disease. Dysregulation of membrane trafficking is a feature of many diseases (neurodegenerative disorders, infections, and cancer), and RAB proteins are increasingly recognized in these contexts (pmc.ncbi.nlm.nih.gov). A broad review in 2011 noted that Rab GTPases are implicated in various human diseases but remain underexplored therapeutically, meaning few drugs target Rab pathways despite their importance (pmc.ncbi.nlm.nih.gov). RAB15, in particular, has been associated with a few pathological and clinical scenarios:

Expert Perspectives: Authoritative reviews consider Rab15 as part of the cellular trafficking network that is often co-opted in disease. A clinical genetics review (Agola et al., 2011) summarized that Rab15 localizes to early and recycling endosomes, mediating trafficking from sorting endosomes back to the plasma membrane (pmc.ncbi.nlm.nih.gov). Unlike some Rabs, Rab15 has not been directly linked to a defined genetic disorder, but experts emphasize that many Rab GTPases (and their regulators) contribute to organ-specific diseases when mutated or misregulated (pmc.ncbi.nlm.nih.gov). For instance, other Rab-family members are known oncogenes or tumor suppressors, and some cause Mendelian syndromes when mutated (e.g., Rab27 in Griscelli syndrome). While Rab15 itself is not yet in that category, its regulatory role in endocytosis could influence phenomena like cell migration or nutrient uptake, which are central to cancer metastasis and metabolic diseases. Thus, researchers posit that understanding Rab15’s interactome and regulation could yield new insights into controlling cell surface receptor levels — an area relevant to conditions like insulin resistance or cancer cell immune evasion. Indeed, the 2022 CRC study suggested that patterns of RAB protein expression (including RAB15) might predict tumor subtype and even immunotherapy responsiveness (www.frontiersin.org) (www.frontiersin.org). High RAB15 expression was associated with the “CMS3” subtype of colorectal cancer, which has distinct metabolic features and frequent RAS mutations (www.frontiersin.org) (www.frontiersin.org). Although RAB15 is not directly targetable today, such findings point to RAB15 as part of a signature that could inform prognosis or treatment stratification.

In summary, RAB15 is a specialized Rab GTPase that regulates early endosome dynamics and the recycling of membrane receptors. It acts as a molecular switch on endosomal membranes, recruiting different effectors to coordinate “fast” vs “slow” recycling routes back to the cell surface. By counterbalancing Rab5, Rab15 fine-tunes the rate of endocytic uptake and prevents unchecked progression to degradation, thereby preserving a pool of recycling receptors. Its function is exemplified in transferrin receptor trafficking and is critical for maintaining cellular iron homeostasis (pmc.ncbi.nlm.nih.gov). Emerging research has expanded Rab15’s relevance to include roles in autophagy and pathogen survival, as well as potential implications in cancer cell physiology. These insights come from both recent primary studies (2023–2024) and expert analyses, reflecting a current understanding that Rab15, though once relatively obscure, is an important node in the membrane trafficking network with connections to human health. Ongoing studies are likely to further elucidate its regulation (e.g. identifying its GEFs/GAPs) and how its dysfunction may contribute to disease. Given that membrane trafficking is fundamental to processes like nutrient uptake, receptor signaling, and antigen presentation, Rab15 and its pathway could become targets of interest for therapeutic intervention or biomarkers for diseases where cell surface receptor recycling is disrupted. Future research will continue to clarify the precise molecular mechanisms of Rab15 and how this small GTPase can be manipulated to benefit human health.

References:

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  33. AnnotationURLCitation(end_index=15354, start_index=15194, title='Rep15 interacts with several Rab GTPases and has a distinct fold for a Rab effector | Nature Communications', type='url_citation', url='https://www.nature.com/articles/s41467-022-31831-1#:~:text=that%20it%20has%20distinct%20roles,Rab15%20effector%20molecule%20that%20regulates')
  34. AnnotationURLCitation(end_index=15978, start_index=15843, title='Rep15 interacts with several Rab GTPases and has a distinct fold for a Rab effector | Nature Communications', type='url_citation', url='https://www.nature.com/articles/s41467-022-31831-1#:~:text=In%20their%20GTP,structure%20that%20is%20distinct%20from')
  35. AnnotationURLCitation(end_index=16301, start_index=16143, title='Rep15 interacts with several Rab GTPases and has a distinct fold for a Rab effector | Nature Communications', type='url_citation', url='https://www.nature.com/articles/s41467-022-31831-1#:~:text=Rep15%20forms%20a%20stable%20complex,binding%20mode%2C%20we%20have%20determined')
  36. AnnotationURLCitation(end_index=16594, start_index=16453, title='Rab15 Effector Protein: A Novel Protein for Receptor Recycling from the Endocytic Recycling Compartment - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC1289414/#:~:text=protein%20,recycling%20from%20the%20endocytic%20recycling')
  37. AnnotationURLCitation(end_index=16753, start_index=16595, title='Rep15 interacts with several Rab GTPases and has a distinct fold for a Rab effector | Nature Communications', type='url_citation', url='https://www.nature.com/articles/s41467-022-31831-1#:~:text=Rep15%20forms%20a%20stable%20complex,binding%20mode%2C%20we%20have%20determined')
  38. AnnotationURLCitation(end_index=17003, start_index=16831, title='Rep15 interacts with several Rab GTPases and has a distinct fold for a Rab effector | Nature Communications', type='url_citation', url='https://www.nature.com/articles/s41467-022-31831-1#:~:text=interaction%20partners%20and%20further%20validated,binding%20mode%2C%20we%20have%20determined')
  39. AnnotationURLCitation(end_index=17825, start_index=17636, title='Rab15 Effector Protein: A Novel Protein for Receptor Recycling from the Endocytic Recycling Compartment - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC1289414/#:~:text=Consistent%20with%20its%20localization%2C%20REP15,recycling%20are%20mechanistically%20distinct%20pathways')
  40. AnnotationURLCitation(end_index=18715, start_index=18534, title='Rab15 differentially regulates early endocytic trafficking - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/10837464/#:~:text=that%20HArab15%20may%20counteract%20the,early%2Fsorting%20and%20pericentriolar%20recycling%20endosomes')
  41. AnnotationURLCitation(end_index=19615, start_index=19526, title='Vesicular transport in the autophagic route: RAB GTPases as pivotal regulators of autophagy - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC12687433/#:~:text=,111')
  42. AnnotationURLCitation(end_index=19881, start_index=19792, title='Vesicular transport in the autophagic route: RAB GTPases as pivotal regulators of autophagy - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC12687433/#:~:text=,111')
  43. AnnotationURLCitation(end_index=20424, start_index=20299, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=%28T4SS%29%20effector%20Etf,chaffeensis%20using%20confocal')
  44. AnnotationURLCitation(end_index=20517, start_index=20425, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=2,chaffeensis%20Infection')
  45. AnnotationURLCitation(end_index=20831, start_index=20706, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=%28T4SS%29%20effector%20Etf,chaffeensis%20using%20confocal')
  46. AnnotationURLCitation(end_index=20949, start_index=20832, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=RAB15%3B%20type%20IV%20secretion%20system,effector')
  47. AnnotationURLCitation(end_index=21256, start_index=21167, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=microscopy,chaffeensis')
  48. AnnotationURLCitation(end_index=21379, start_index=21257, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=localized%20on%20lysosomes%20,1%20cells%20compared%20to')
  49. AnnotationURLCitation(end_index=21607, start_index=21501, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=whether%20RAB15%20is%20involved%20in,We')
  50. AnnotationURLCitation(end_index=22002, start_index=21869, title='Vesicular transport in the autophagic route: RAB GTPases as pivotal regulators of autophagy - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC12687433/#:~:text=depletion%20promotes%20the%20maturation%20of,102')
  51. AnnotationURLCitation(end_index=22092, start_index=22003, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=microscopy,chaffeensis')
  52. AnnotationURLCitation(end_index=22547, start_index=22458, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=microscopy,chaffeensis')
  53. AnnotationURLCitation(end_index=22670, start_index=22548, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=localized%20on%20lysosomes%20,1%20cells%20compared%20to')
  54. AnnotationURLCitation(end_index=23357, start_index=23222, title='Rab GTPases as regulators of endocytosis, targets of disease and therapeutic opportunities - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3187864/#:~:text=Rab%20GTPases%20are%20well,The%20broad%20range%20of')
  55. AnnotationURLCitation(end_index=23688, start_index=23553, title='Rab GTPases as regulators of endocytosis, targets of disease and therapeutic opportunities - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3187864/#:~:text=Rab%20GTPases%20are%20well,The%20broad%20range%20of')
  56. AnnotationURLCitation(end_index=24260, start_index=24085, title='Frontiers | The Role of RAB GTPases and Its Potential in Predicting Immunotherapy Response and Prognosis in Colorectal Cancer', type='url_citation', url='https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.828373/full#:~:text=Results%3A%20Of%20the%2062%20RABs,RABs%2C%20which%20were')
  57. AnnotationURLCitation(end_index=24567, start_index=24392, title='Frontiers | The Role of RAB GTPases and Its Potential in Predicting Immunotherapy Response and Prognosis in Colorectal Cancer', type='url_citation', url='https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.828373/full#:~:text=Results%3A%20Of%20the%2062%20RABs,RABs%2C%20which%20were')
  58. AnnotationURLCitation(end_index=25031, start_index=24920, title='Consequences of Rab GTPase dysfunction in genetic or acquired human diseases - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5902184/#:~:text=diseases%20,231%20and%20PC3')
  59. AnnotationURLCitation(end_index=25425, start_index=25273, title='Rep15 interacts with several Rab GTPases and has a distinct fold for a Rab effector | Nature Communications', type='url_citation', url='https://www.nature.com/articles/s41467-022-31831-1#:~:text=bMERB%20family%20members%2C%20Rep15%20is,depletion%20of%20Rep15%20by%20si')
  60. AnnotationURLCitation(end_index=26763, start_index=26642, title='Consequences of Rab GTPase dysfunction in genetic or acquired human diseases - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5902184/#:~:text=Marcellus%20J%20Banworth%20,%E2%9C%89')
  61. AnnotationURLCitation(end_index=26874, start_index=26764, title='Consequences of Rab GTPase dysfunction in genetic or acquired human diseases - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5902184/#:~:text=Skip%20to%20main%20content')
  62. AnnotationURLCitation(end_index=27247, start_index=27122, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=%28T4SS%29%20effector%20Etf,chaffeensis%20using%20confocal')
  63. AnnotationURLCitation(end_index=27337, start_index=27248, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=microscopy,chaffeensis')
  64. AnnotationURLCitation(end_index=28111, start_index=27976, title='Rab GTPases as regulators of endocytosis, targets of disease and therapeutic opportunities - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3187864/#:~:text=Rab%20GTPases%20are%20well,The%20broad%20range%20of')
  65. AnnotationURLCitation(end_index=28600, start_index=28448, title='Rab GTPases as regulators of endocytosis, targets of disease and therapeutic opportunities - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3187864/#:~:text=Rab14%20%20,induced%20apoptosis%3B%20phagosome%20acidification%20and')
  66. AnnotationURLCitation(end_index=28957, start_index=28822, title='Rab GTPases as regulators of endocytosis, targets of disease and therapeutic opportunities - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3187864/#:~:text=Rab%20GTPases%20are%20well,The%20broad%20range%20of')
  67. AnnotationURLCitation(end_index=29898, start_index=29735, title='Frontiers | The Role of RAB GTPases and Its Potential in Predicting Immunotherapy Response and Prognosis in Colorectal Cancer', type='url_citation', url='https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.828373/full#:~:text=,vitro%20experiments%20showed%20that%20RAB17')
  68. AnnotationURLCitation(end_index=30087, start_index=29899, title='Frontiers | The Role of RAB GTPases and Its Potential in Predicting Immunotherapy Response and Prognosis in Colorectal Cancer', type='url_citation', url='https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.828373/full#:~:text=cell%20cycle%20and%20immune,and%20immunotherapy%20response%20in%20CRC')
  69. AnnotationURLCitation(end_index=30428, start_index=30237, title='Frontiers | The Role of RAB GTPases and Its Potential in Predicting Immunotherapy Response and Prognosis in Colorectal Cancer', type='url_citation', url='https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.828373/full#:~:text=match%20at%20L311%20analysis%20in,test.%20%28C%E2%80%93D%29%20Gene%20set')
  70. AnnotationURLCitation(end_index=30624, start_index=30429, title='Frontiers | The Role of RAB GTPases and Its Potential in Predicting Immunotherapy Response and Prognosis in Colorectal Cancer', type='url_citation', url='https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.828373/full#:~:text=curves%20of%20the%20upregulated,RAB12%2C%20RAB23%2C%20RAB31%2C%20and%20RAB34')
  71. AnnotationURLCitation(end_index=31560, start_index=31371, title='Rab15 Effector Protein: A Novel Protein for Receptor Recycling from the Endocytic Recycling Compartment - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC1289414/#:~:text=Consistent%20with%20its%20localization%2C%20REP15,recycling%20are%20mechanistically%20distinct%20pathways')
  72. AnnotationURLCitation(end_index=33014, start_index=32853, title='Rep15 interacts with several Rab GTPases and has a distinct fold for a Rab effector | Nature Communications', type='url_citation', url='https://www.nature.com/articles/s41467-022-31831-1#:~:text=Rab15%20is%20enriched%20explicitly%20in,additional%20studies%20are%20required%20to')
  73. AnnotationURLCitation(end_index=33163, start_index=33015, title='Reactome | UniProt:P59190 RAB15', type='url_citation', url='https://www.reactome.org/content/schema/instance/browser/uniprot%3AP59190#:~:text=active%20GTP,GTP%20bound%20form%20of%20RAB15')
  74. AnnotationURLCitation(end_index=33443, start_index=33300, title='Rab15 differentially regulates early endocytic trafficking - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/10837464/#:~:text=in%20the%20rate%20of%20homotypic,effect%20of%20Rab5%20on%20early')
  75. AnnotationURLCitation(end_index=33625, start_index=33444, title='Rab15 differentially regulates early endocytic trafficking - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/10837464/#:~:text=that%20HArab15%20may%20counteract%20the,early%2Fsorting%20and%20pericentriolar%20recycling%20endosomes')
  76. AnnotationURLCitation(end_index=33925, start_index=33784, title='Rab15 Effector Protein: A Novel Protein for Receptor Recycling from the Endocytic Recycling Compartment - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC1289414/#:~:text=protein%20,recycling%20from%20the%20endocytic%20recycling')
  77. AnnotationURLCitation(end_index=34115, start_index=33926, title='Rab15 Effector Protein: A Novel Protein for Receptor Recycling from the Endocytic Recycling Compartment - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC1289414/#:~:text=Consistent%20with%20its%20localization%2C%20REP15,recycling%20are%20mechanistically%20distinct%20pathways')
  78. AnnotationURLCitation(end_index=34390, start_index=34238, title='Rab GTPases as regulators of endocytosis, targets of disease and therapeutic opportunities - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3187864/#:~:text=Rab14%20%20,induced%20apoptosis%3B%20phagosome%20acidification%20and')
  79. AnnotationURLCitation(end_index=34557, start_index=34391, title='Rab GTPases as regulators of endocytosis, targets of disease and therapeutic opportunities - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3187864/#:~:text=early%20endosome%20segregates%20molecules%20for,as%20well%20as%20for%20degradation')
  80. AnnotationURLCitation(end_index=34998, start_index=34822, title='Rab15 expression correlates with retinoic acid-induced differentiation of neuroblastoma cells - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21491086/#:~:text=spliced%20Rab15%20isoforms%20designated%20as,induced%20differentiation%20of%20newly%20established')
  81. AnnotationURLCitation(end_index=35179, start_index=34999, title='Rab15 expression correlates with retinoic acid-induced differentiation of neuroblastoma cells - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21491086/#:~:text=RA%20induced%20neuronal%20differentiation%20of,induced%20differentiation%20of%20neuroblastoma%20cells')
  82. AnnotationURLCitation(end_index=35826, start_index=35651, title='Frontiers | The Role of RAB GTPases and Its Potential in Predicting Immunotherapy Response and Prognosis in Colorectal Cancer', type='url_citation', url='https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.828373/full#:~:text=Results%3A%20Of%20the%2062%20RABs,RABs%2C%20which%20were')
  83. AnnotationURLCitation(end_index=36116, start_index=35981, title='Rep15 interacts with several Rab GTPases and has a distinct fold for a Rab effector | Nature Communications', type='url_citation', url='https://www.nature.com/articles/s41467-022-31831-1#:~:text=In%20their%20GTP,structure%20that%20is%20distinct%20from')
  84. AnnotationURLCitation(end_index=36257, start_index=36117, title='Rep15 interacts with several Rab GTPases and has a distinct fold for a Rab effector | Nature Communications', type='url_citation', url='https://www.nature.com/articles/s41467-022-31831-1#:~:text=Rab15%20is%20enriched%20explicitly%20in,14%7D%2C%20suggesting')
  85. AnnotationURLCitation(end_index=36551, start_index=36426, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=%28T4SS%29%20effector%20Etf,chaffeensis%20using%20confocal')
  86. AnnotationURLCitation(end_index=36641, start_index=36552, title='Ehrlichia chaffeensis Etf-3 Induces Host RAB15 Upregulation for Bacterial Intracellular Growth', type='url_citation', url='https://www.mdpi.com/1422-0067/25/5/2551#:~:text=microscopy,chaffeensis')
  87. AnnotationURLCitation(end_index=36912, start_index=36823, title='Vesicular transport in the autophagic route: RAB GTPases as pivotal regulators of autophagy - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC12687433/#:~:text=,111')