Biology subjects

Pedicini, L.

Publications and source records attributed to Pedicini, L..

3 recordsLinked to original sources

bioRxiv2024

RNAseq analysis reveals transcriptome changes associated with the progression of non-alcoholic liver disease in livers from Efcab4b knockout mice

EFCAB4B is an evolutionarily conserved protein that encodes for the Rab GTPase Rab46, and the CRAC channel modulator, CRACR2A. Previous genome wide association studies have demonstrated the association of EFCAB4B variants in the progression of non-alcoholic liver disease (NAFLD). In this study we show that mice with global depletion of Efcab4b-/- have significantly larger livers than their wild-type (WT) counterparts. We performed RNA-sequencing (RNA-seq) analysis of liver tissues to investigate differential global gene expression among Efcab4b-/-and WT mice. Of the 69 differentially expressed genes (DEGs), analyses of biological processes found significant enrichment in liver and bile development, with 6 genes (Pck1, Aacs, Onecut1, E2f8, Xbp1, and Hes1) involved in both processes. Specific consideration of possible roles of DEGs or their products in NAFLD progression to (NASH) and hepatocarcinoma (HCC), demonstrated DEGs in the livers of Efcab4b-/- mice had roles in molecular pathways including lipid metabolism, inflammation, ER stress and fibrosis. The results in this study provide additional insights into molecular mechanisms responsible for increasing susceptibility of liver injuries associated with EFCAB4B.

genetics↗

bioRxiv2023

Rab46: a novel player in mast cell function

Mast cells are infamous for mediating allergic and inflammatory diseases due to their capacity of rapidly releasing a wide range of inflammatory mediators stored in cytoplasmic granules. However, mast cells also have several important physiological roles that involves selective and agonist-specific release of these active mediators. Whilst a filtering mechanism at the plasma membrane could regulate selective release of some cargo, the plethora of stored cargo and the diversity of mast cell functions suggests the existence of granule subtypes with distinct trafficking pathways. The molecular mechanisms underlying differential trafficking and exocytosis of these granules are not known, neither is it clear how granule trafficking is coupled to the stimulus. In endothelial cells, a Rab GTPase, Rab46, responds to histamine but not thrombin signals, and this regulates the trafficking of a subpopulation of endothelial-specific granules. Here, we sought to explore if Rab46 has a similar function in mast cells. We demonstrate, for the first time, that Rab46 is highly expressed in human and murine mast cells and Rab46 genetic deletion has an effect on mast cell degranulation that depends on both stimuli and mast cell developmental stage. Rab46 could therefore be an important regulator of stimuli-coupled responses in mast cells and future studies will seek to understand these mechanisms in order to develop novel and specific therapeutic targets for treatment of the diverse pathologies mediated by mast cells.

cell biology↗

bioRxiv2020

Identification of novel Rab46 effector proteins

Rab46 is a novel Ca2+- sensing Rab GTPase shown to have important functions in endothelial and immune cells. The presence of functional Ca2+- binding, coiled-coil and Rab domains suggest that Rab46 will be important for coupling rapid responses to signalling in many cell types. The molecular mechanisms underlying Rab46 function are currently unknown. Here we provide the first resource for studying Rab46 interacting proteins. Using liquid chromatography mass spectrometry (LC-MS/MS) to identify affinity purified proteins that bind to constitutively active GFP-Rab46 or inactive GFP-Rab46 expressed in endothelial cells, we have revealed 922 possible interacting proteins. Further comparative analyses between nucleotide-locked Rab46 proteins enriched this dataset to confidently identify 29 effector proteins. Importantly, through biochemical and imaging approaches we have validated two potential effector proteins; dynein and the Na2+/ K+ ATPase subunit alpha 1 (ATP1α1). Hence, our use of affinity purification and LC-MS/MS to identify Rab46 neighbouring proteins provides a valuable resource for detecting Rab46 effector proteins and analysing Rab46 functions.Competing Interest StatementThe authors have declared no competing interest.AbbreviationsLC-MS/MSliquid chromatography mass spectrometryGEFsliquid chromatography mass spectrometrGAPsGTPase activating proteinsWPBsWeibel-Palade bodiesECsendothelial cellsMTOCmicrotubule organising centreFDRfalse discovery rateDHCdynein heavy chainATP1α1Na2+/ K+ ATPase subunit α1View Full Text

cell biology↗