| Structural highlights
Function
[RAB10_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 (By similarity). That Rab is mainly involved in the biosynthetic transport of proteins from the Golgi to the plasma membrane. Regulates, for instance, SLC2A4/GLUT4 glucose transporter-enriched vesicles delivery to the plasma membrane. In parallel, it regulates the transport of TLR4, a toll-like receptor to the plasma membrane and therefore may be important for innate immune response. Plays also a specific role in asymmetric protein transport to the plasma membrane within the polarized neuron and epithelial cells. In neurons, it is involved in axonogenesis through regulation of vesicular membrane trafficking toward the axonal plasma membrane while in epithelial cells, it regulates transport from the Golgi to the basolateral membrane. Moreover, may play a role in the basolateral recycling pathway and in phagosome maturation. According to PubMed:23263280, may play a role in endoplasmic reticulum dynamics and morphology controlling tubulation along microtubules and tubules fusion.[1] [2] [3] [MICA1_HUMAN] Monooxygenase that promotes depolymerization of F-actin by mediating oxidation of specific methionine residues on actin. Acts by modifying actin subunits through the addition of oxygen to form methionine-sulfoxide, leading to promote actin filament severing and prevent repolymerization (Probable). Acts as a cytoskeletal regulator that connects NEDD9 to intermediate filaments. Also acts as a negative regulator of apoptosis via its interaction with STK38 and STK38L; acts by antagonizing STK38 and STK38L activation by MST1/STK4.[4] [5]
Publication Abstract from PubMed
In their active GTP-bound form, Rab proteins interact with proteins termed effector molecules. In this study we have thoroughly characterised a Rab effector domain that is present in proteins of the Mical and EHBP families, both known to act in endosomal trafficking. Within our study, we show that these effectors display a preference for Rab8 family proteins (Rab8, 10, 13 and 15) and that some of the effector domains can bind two Rab proteins via separate binding sites. Structural analysis allowed us to explain the specificity towards Rab8 family members and the presence of two similar Rab binding sites that must have evolved via gene duplication. This study is the first to thoroughly characterise a Rab effector protein that contains two separate Rab binding sites within a single domain, allowing Micals and EHBPs to bind two Rabs simultaneously, thus suggesting previously unknown functions of these effector molecules in endosomal trafficking.
bMERB domains are bivalent Rab8 family effectors evolved by gene duplication.,Rai A, Oprisko A, Campos J, Fu Y, Friese T, Itzen A, Goody RS, Gazdag EM, Muller MP Elife. 2016 Aug 23;5. pii: e18675. doi: 10.7554/eLife.18675. PMID:27552051[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Babbey CM, Ahktar N, Wang E, Chen CC, Grant BD, Dunn KW. Rab10 regulates membrane transport through early endosomes of polarized Madin-Darby canine kidney cells. Mol Biol Cell. 2006 Jul;17(7):3156-75. Epub 2006 Apr 26. PMID:16641372 doi:http://dx.doi.org/10.1091/mbc.E05-08-0799
- ↑ Hutagalung AH, Novick PJ. Role of Rab GTPases in membrane traffic and cell physiology. Physiol Rev. 2011 Jan;91(1):119-49. doi: 10.1152/physrev.00059.2009. PMID:21248164 doi:http://dx.doi.org/10.1152/physrev.00059.2009
- ↑ English AR, Voeltz GK. Rab10 GTPase regulates ER dynamics and morphology. Nat Cell Biol. 2013 Feb;15(2):169-78. doi: 10.1038/ncb2647. Epub 2012 Dec 23. PMID:23263280 doi:http://dx.doi.org/10.1038/ncb2647
- ↑ Schmidt EF, Shim SO, Strittmatter SM. Release of MICAL autoinhibition by semaphorin-plexin signaling promotes interaction with collapsin response mediator protein. J Neurosci. 2008 Feb 27;28(9):2287-97. doi: 10.1523/JNEUROSCI.5646-07.2008. PMID:18305261 doi:http://dx.doi.org/10.1523/JNEUROSCI.5646-07.2008
- ↑ Zucchini D, Caprini G, Pasterkamp RJ, Tedeschi G, Vanoni MA. Kinetic and spectroscopic characterization of the putative monooxygenase domain of human MICAL-1. Arch Biochem Biophys. 2011 Nov;515(1-2):1-13. doi: 10.1016/j.abb.2011.08.004., Epub 2011 Aug 16. PMID:21864500 doi:http://dx.doi.org/10.1016/j.abb.2011.08.004
- ↑ Rai A, Oprisko A, Campos J, Fu Y, Friese T, Itzen A, Goody RS, Gazdag EM, Muller MP. bMERB domains are bivalent Rab8 family effectors evolved by gene duplication. Elife. 2016 Aug 23;5. pii: e18675. doi: 10.7554/eLife.18675. PMID:27552051 doi:http://dx.doi.org/10.7554/eLife.18675
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