{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nRab11b functions as a pivotal regulator of polarized recycling pathways that ensure proper plasma membrane composition and cell homeostasis. In epithelial cells, Rab11b is uniquely required for the efficient apical recycling of the cystic fibrosis transmembrane conductance regulator (CFTR), thereby maintaining optimal channel density and function. Similarly, in salivary duct cells facing extracellular acidosis, Rab11b drives the translocation of the vacuolar‐type H⁺‑ATPase (V‑ATPase) from intracellular stores to the plasma membrane, and its inhibition or depletion leads to impaired transporter delivery. In cardiac myocytes and HEK293 cells, diminished Rab11b function slows the degradation of Ca(v)1.2 L‑type Ca²⁺ channels, resulting in increased channel surface density and altered electrophysiological properties."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "3"}]}, {"type": "t", "text": "\n\nRab11b also orchestrates specialized secretory and developmental processes through its targeted vesicular transport functions. In melanocytes, Rab11b is essential for keratinocyte-induced exocytosis of melanocores, thereby regulating melanin transfer and skin pigmentation. In apicomplexan parasites, such as Toxoplasma gondii, this Rab GTPase is alveolate-specific and mediates the directed delivery of Golgi-derived vesicles to the growing inner membrane complex, a step crucial for daughter cell formation. In the context of cancer biology, Rab11b directs the recycling of integrin β1 to the plasma membrane in breast cancer cells, promoting mechanotransduction and adaptation to the brain microenvironment during metastasis. Additionally, its selective interaction with the leucine zipper domain of type II cGMP‑dependent protein kinase underscores its role in precise protein targeting."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "4", "end_ref": "7"}]}, {"type": "t", "text": "\n\nStructural and cellular investigations further delineate how Rab11b’s unique molecular features underpin its specialized trafficking roles relative to other Rab11 isoforms. High-resolution crystallographic studies reveal distinct conformational properties of Rab11b’s nucleotide‑binding and switch regions that may influence its GTP hydrolysis rate and effector selectivity. In parallel, genetic ablation and knockdown experiments highlight overlapping yet nonredundant roles for Rab11b alongside Rab11a, as loss of either isoform perturbs endosomal morphology and disrupts receptor recycling dynamics. Collectively, these findings establish Rab11b as a critical nexus in vesicular transport and endosomal sorting, impacting diverse physiological and pathological processes."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "8"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Mark R Silvis, Carol A Bertrand, Nadia Ameen, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Rab11b regulates the apical recycling of the cystic fibrosis transmembrane conductance regulator in polarized intestinal epithelial cells."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Mol Biol Cell (2009)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1091/mbc.e08-01-0084"}], "href": "https://doi.org/10.1091/mbc.e08-01-0084"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "19244346"}], "href": "https://pubmed.ncbi.nlm.nih.gov/19244346"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Oliver Oehlke, Cornelius Schlosshardt, Melanie Feuerstein, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Acidosis-induced V-ATPase trafficking in salivary ducts is initiated by cAMP/PKA/CREB pathway via regulation of Rab11b expression."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Int J Biochem Cell Biol (2012)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.biocel.2012.04.018"}], "href": "https://doi.org/10.1016/j.biocel.2012.04.018"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "22561749"}], "href": "https://pubmed.ncbi.nlm.nih.gov/22561749"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Ellen M Haugsten, Andreas Brech, Knut Liestøl, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Photoactivation approaches reveal a role for Rab11 in FGFR4 recycling and signalling."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Traffic (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1111/tra.12168"}], "href": "https://doi.org/10.1111/tra.12168"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "24589086"}], "href": "https://pubmed.ncbi.nlm.nih.gov/24589086"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Carolina Agop-Nersesian, Saskia Egarter, Gordon Langsley, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Biogenesis of the inner membrane complex is dependent on vesicular transport by the alveolate specific GTPase Rab11B."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS Pathog (2010)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.ppat.1001029"}], "href": "https://doi.org/10.1371/journal.ppat.1001029"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "20686666"}], "href": "https://pubmed.ncbi.nlm.nih.gov/20686666"}]}, {"type": "r", "ref": 5, "children": [{"type": "t", "text": "Abul K Tarafder, Giulia Bolasco, Maria S Correia, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Rab11b mediates melanin transfer between donor melanocytes and acceptor keratinocytes via coupled exo/endocytosis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Invest Dermatol (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1038/jid.2013.432"}], "href": "https://doi.org/10.1038/jid.2013.432"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "24141907"}], "href": "https://pubmed.ncbi.nlm.nih.gov/24141907"}]}, {"type": "r", "ref": 6, "children": [{"type": "t", "text": "Albert S Reger, Matthew P Yang, Shizuyo Koide-Yoshida, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Crystal structure of the cGMP-dependent protein kinase II leucine zipper and Rab11b protein complex reveals molecular details of G-kinase-specific interactions."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Biol Chem (2014)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1074/jbc.M114.575894"}], "href": "https://doi.org/10.1074/jbc.M114.575894"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "25070890"}], "href": "https://pubmed.ncbi.nlm.nih.gov/25070890"}]}, {"type": "r", "ref": 7, "children": [{"type": "t", "text": "Erin N Howe, Miranda D Burnette, Melanie E Justice, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Rab11b-mediated integrin recycling promotes brain metastatic adaptation and outgrowth."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Nat Commun (2020)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1038/s41467-020-16832-2"}], "href": "https://doi.org/10.1038/s41467-020-16832-2"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "32541798"}], "href": "https://pubmed.ncbi.nlm.nih.gov/32541798"}]}, {"type": "r", "ref": 8, "children": [{"type": "t", "text": "Sandra M N Scapin, Flávia R G Carneiro, Adriana C Alves, et al. "}, {"type": "b", "children": [{"type": "t", "text": "The crystal structure of the small GTPase Rab11b reveals critical differences relative to the Rab11a isoform."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Struct Biol (2006)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.jsb.2006.01.007"}], "href": "https://doi.org/10.1016/j.jsb.2006.01.007"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "16545962"}], "href": "https://pubmed.ncbi.nlm.nih.gov/16545962"}]}, {"type": "r", "ref": 9, "children": [{"type": "t", "text": "Ideke J C Lamers, Margot R F Reijnders, Hanka Venselaar, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Recurrent De Novo Mutations Disturbing the GTP/GDP Binding Pocket of RAB11B Cause Intellectual Disability and a Distinctive Brain Phenotype."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Am J Hum Genet (2017)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1016/j.ajhg.2017.09.015"}], "href": "https://doi.org/10.1016/j.ajhg.2017.09.015"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "29106825"}], "href": "https://pubmed.ncbi.nlm.nih.gov/29106825"}]}]}]}