4d0m
From Proteopedia
Phosphatidylinositol 4-kinase III beta in a complex with Rab11a-GTP- gamma-S and the Rab-binding domain of FIP3
Structural highlights
Function[PI4KB_HUMAN] Phosphorylates phosphatidylinositol (PI) in the first committed step in the production of the second messenger inositol-1,4,5,-trisphosphate (PIP). May regulate Golgi disintegration/reorganization during mitosis, possibly via its phosphorylation. Involved in Golgi-to-plasma membrane trafficking (By similarity).[1] [2] [3] [RFIP3_HUMAN] Acts as a regulator of endocytic traffic by participating in membrane delivery. Required for the abcission step in cytokinesis, possibly by acting as an 'address tag' delivering recycling endosome membranes to the cleavage furrow during late cytokinesis. Also required for the structural integrity of the endosomal recycling compartment during interphase. May play a role in breast cancer cell motility by regulating actin cytoskeleton.[4] [5] [6] [RB11A_HUMAN] The small GTPases Rab are key regulators of intracellular membrane trafficking, from the formation of transport vesicles to their fusion with membranes. Rabs cycle between an inactive GDP-bound form and an active GTP-bound form that is able to recruit to membranes different set of downstream effectors directly responsible for vesicle formation, movement, tethering and fusion. That Rab regulates endocytic recycling. Acts as a major regulator of membrane delivery during cytokinesis. Together with MYO5B and RAB8A participates in epithelial cell polarization. Together with RAB3IP, RAB8A, the exocyst complex, PARD3, PRKCI, ANXA2, CDC42 and DNMBP promotes transcytosis of PODXL to the apical membrane initiation sites (AMIS), apical surface formation and lumenogenesis. Together with MYO5B participates in CFTR trafficking to the plasma membrane and TF (Transferrin) recycling in nonpolarized cells. Required in a complex with MYO5B and RAB11FIP2 for the transport of NPC1L1 to the plasma membrane. Participates in the sorting and basolateral transport of CDH1 from the Golgi apparatus to the plasma membrane. Regulates the recycling of FCGRT (receptor of Fc region of monomeric Ig G) to basolateral membranes. May also play a role in melanosome transport and release from melanocytes.[7] [8] [9] [10] [11] [12] Publication Abstract from PubMedPhosphatidylinositol 4-kinases (PI4Ks) and small guanosine triphosphatases (GTPases) are essential for processes that require expansion and remodeling of phosphatidylinositol 4-phosphate (PI4P)-containing membranes, including cytokinesis, intracellular development of malarial pathogens, and replication of a wide range of RNA viruses. However, the structural basis for coordination of PI4K, GTPases, and their effectors is unknown. Here, we describe structures of PI4Kbeta (PI4KIIIbeta) bound to the small GTPase Rab11a without and with the Rab11 effector protein FIP3. The Rab11-PI4KIIIbeta interface is distinct compared with known structures of Rab complexes and does not involve switch regions used by GTPase effectors. Our data provide a mechanism for how PI4KIIIbeta coordinates Rab11 and its effectors on PI4P-enriched membranes and also provide strategies for the design of specific inhibitors that could potentially target plasmodial PI4KIIIbeta to combat malaria. Structures of PI4KIIIbeta complexes show simultaneous recruitment of Rab11 and its effectors.,Burke JE, Inglis AJ, Perisic O, Masson GR, McLaughlin SH, Rutaganira F, Shokat KM, Williams RL Science. 2014 May 30;344(6187):1035-8. doi: 10.1126/science.1253397. PMID:24876499[13] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: 1-phosphatidylinositol 4-kinase | Human | Burke, J E | Inglis, A J | Masson, G R | McLaughlin, S H | Perisic, O | Rutaganira, F | Shokat, K M | Williams, R L | Family of rab interacting protein | Fip3 | Golgi | Gtp | Lipid kinase | Phosphatidylinositol 4-kinase | Phosphoinositide | Pik93 | Rab-binding domain | Rab11 | Rbd | Recycling endosome | Signaling protein
