Structural highlights
Function
[RAB8A_HUMAN] May be involved in vesicular trafficking and neurotransmitter release. Together with RAB11A, RAB3IP, 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 and RAB11A participates in epithelial cell polarization.[1] [2] [MICLK_HUMAN] May cooperate with MAPK1/ERK2 via an intracellular signal transduction pathway in the morphogenetic development of round spermatids to spermatozoa.
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[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Bryant DM, Datta A, Rodriguez-Fraticelli AE, Peranen J, Martin-Belmonte F, Mostov KE. A molecular network for de novo generation of the apical surface and lumen. Nat Cell Biol. 2010 Nov;12(11):1035-45. doi: 10.1038/ncb2106. Epub 2010 Oct 3. PMID:20890297 doi:10.1038/ncb2106
- ↑ Roland JT, Bryant DM, Datta A, Itzen A, Mostov KE, Goldenring JR. Rab GTPase-Myo5B complexes control membrane recycling and epithelial polarization. Proc Natl Acad Sci U S A. 2011 Feb 15;108(7):2789-94. doi:, 10.1073/pnas.1010754108. Epub 2011 Jan 31. PMID:21282656 doi:10.1073/pnas.1010754108
- ↑ 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
