2hv8 | pdb_00002hv8
Crystal structure of GTP-bound Rab11 in complex with FIP3
Structural highlights
Function[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.[1] [2] [3] [4] [5] [6] [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.[7] [8] [9] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe Rab11 GTPase regulates recycling of internalized plasma membrane receptors and is essential for completion of cytokinesis. A family of Rab11 interacting proteins (FIPs) that conserve a C-terminal Rab-binding domain (RBD) selectively recognize the active form of Rab11. Normal completion of cytokinesis requires a complex between Rab11 and FIP3. Here, we report the crystal structure and mutational analysis of a heterotetrameric complex between constitutively active Rab11 and a FIP3 construct that includes the RBD. Two Rab11 molecules bind to dyad symmetric sites at the C terminus of FIP3, which forms a non-canonical coiled-coiled dimer with a flared C terminus and hook region. The RBD overlaps with the coiled coil and extends through the C-terminal hook. Although FIP3 engages the switch and interswitch regions of Rab11, the mode of interaction differs significantly from that of other Rab-effector complexes. In particular, the switch II region undergoes a large structural rearrangement from an ordered but non-complementary active conformation to a remodeled conformation that facilitates the interaction with FIP3. Finally, we provide evidence that FIP3 can form homo-oligomers in cells, and that a critical determinant of Rab11 binding in vitro is necessary for FIP3 recruitment to recycling endosomes during cytokinesis. Structural basis for Rab11-mediated recruitment of FIP3 to recycling endosomes.,Eathiraj S, Mishra A, Prekeris R, Lambright DG J Mol Biol. 2006 Nov 24;364(2):121-35. Epub 2006 Aug 26. PMID:17007872[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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