Limits...
Comparative proteomic analysis of compartmentalised Ras signalling.

Hernandez-Valladares M, Prior IA - Sci Rep (2015)

Bottom Line: However, the extent to which intracellular pools of Ras can contribute to cell signalling is debated.Our data reveal that ~80% of phosphosites exhibiting large (≥1.5-fold) changes compared to control can be modulated by organellar Ras signalling.Our analysis reinforces the concept that compartmentalisation influences Ras signalling and provides detailed insight into the widespread modulation of responses downstream of endomembranous Ras signalling.

View Article: PubMed Central - PubMed

Affiliation: Physiological Laboratory, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, United Kingdom.

ABSTRACT
Ras proteins are membrane bound signalling hubs that operate from both the cell surface and endomembrane compartments. However, the extent to which intracellular pools of Ras can contribute to cell signalling is debated. To address this, we have performed a global screen of compartmentalised Ras signalling. We find that whilst ER/Golgi- and endosomal-Ras only generate weak outputs, Ras localised to the mitochondria or Golgi significantly and distinctly influence both the abundance and phosphorylation of a wide range of proteins analysed. Our data reveal that ~80% of phosphosites exhibiting large (≥1.5-fold) changes compared to control can be modulated by organellar Ras signalling. The majority of compartmentalised Ras-specific responses are predicted to influence gene expression, RNA splicing and cell proliferation. Our analysis reinforces the concept that compartmentalisation influences Ras signalling and provides detailed insight into the widespread modulation of responses downstream of endomembranous Ras signalling.

No MeSH data available.


Related in: MedlinePlus

Responses within the local Ras signalling network.(A) Ras effector activation downstream of compartmentalised Ras. Mean values +/− SEM of western blot quantitation of phospho-ERK and phospho-AKT normalised to actin are presented. n = 4, *p < 0.05 paired two-tailed T-test. (B) Nodes identified in the phosphoproteome dataset are highlighted in red and exhibit highly distinctive compartment-specific responses.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4664896&req=5

f2: Responses within the local Ras signalling network.(A) Ras effector activation downstream of compartmentalised Ras. Mean values +/− SEM of western blot quantitation of phospho-ERK and phospho-AKT normalised to actin are presented. n = 4, *p < 0.05 paired two-tailed T-test. (B) Nodes identified in the phosphoproteome dataset are highlighted in red and exhibit highly distinctive compartment-specific responses.

Mentions: The network response to Ras activation is likely to be significantly influenced by the signal flow through the Raf-MAP kinase and PtdIns-3-kinase-AKT effector pathways. To provide initial insight into the activation of these canonical effector pathways we used western blotting for phospho-ERK and phospho-AKT and found that whilst NRAS and KRAS elicit potent MAP kinase activation, the organellar Ras locations exhibit weak trends for increased outputs (Fig. 2A). Similar trends are seen for phosphor-AKT responses. Despite the apparently weak outputs associated with the organellar Ras variants examination of collation of the responses of the local Ras network nodes within the phospho-proteomic data revealed organelle-specific responses throughout the network (Fig. 2B). Notably, ER/Golgi-Ras and endo-Ras appeared to be highly distinct from the other Ras variants.


Comparative proteomic analysis of compartmentalised Ras signalling.

Hernandez-Valladares M, Prior IA - Sci Rep (2015)

Responses within the local Ras signalling network.(A) Ras effector activation downstream of compartmentalised Ras. Mean values +/− SEM of western blot quantitation of phospho-ERK and phospho-AKT normalised to actin are presented. n = 4, *p < 0.05 paired two-tailed T-test. (B) Nodes identified in the phosphoproteome dataset are highlighted in red and exhibit highly distinctive compartment-specific responses.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664896&req=5

f2: Responses within the local Ras signalling network.(A) Ras effector activation downstream of compartmentalised Ras. Mean values +/− SEM of western blot quantitation of phospho-ERK and phospho-AKT normalised to actin are presented. n = 4, *p < 0.05 paired two-tailed T-test. (B) Nodes identified in the phosphoproteome dataset are highlighted in red and exhibit highly distinctive compartment-specific responses.
Mentions: The network response to Ras activation is likely to be significantly influenced by the signal flow through the Raf-MAP kinase and PtdIns-3-kinase-AKT effector pathways. To provide initial insight into the activation of these canonical effector pathways we used western blotting for phospho-ERK and phospho-AKT and found that whilst NRAS and KRAS elicit potent MAP kinase activation, the organellar Ras locations exhibit weak trends for increased outputs (Fig. 2A). Similar trends are seen for phosphor-AKT responses. Despite the apparently weak outputs associated with the organellar Ras variants examination of collation of the responses of the local Ras network nodes within the phospho-proteomic data revealed organelle-specific responses throughout the network (Fig. 2B). Notably, ER/Golgi-Ras and endo-Ras appeared to be highly distinct from the other Ras variants.

Bottom Line: However, the extent to which intracellular pools of Ras can contribute to cell signalling is debated.Our data reveal that ~80% of phosphosites exhibiting large (≥1.5-fold) changes compared to control can be modulated by organellar Ras signalling.Our analysis reinforces the concept that compartmentalisation influences Ras signalling and provides detailed insight into the widespread modulation of responses downstream of endomembranous Ras signalling.

View Article: PubMed Central - PubMed

Affiliation: Physiological Laboratory, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, United Kingdom.

ABSTRACT
Ras proteins are membrane bound signalling hubs that operate from both the cell surface and endomembrane compartments. However, the extent to which intracellular pools of Ras can contribute to cell signalling is debated. To address this, we have performed a global screen of compartmentalised Ras signalling. We find that whilst ER/Golgi- and endosomal-Ras only generate weak outputs, Ras localised to the mitochondria or Golgi significantly and distinctly influence both the abundance and phosphorylation of a wide range of proteins analysed. Our data reveal that ~80% of phosphosites exhibiting large (≥1.5-fold) changes compared to control can be modulated by organellar Ras signalling. The majority of compartmentalised Ras-specific responses are predicted to influence gene expression, RNA splicing and cell proliferation. Our analysis reinforces the concept that compartmentalisation influences Ras signalling and provides detailed insight into the widespread modulation of responses downstream of endomembranous Ras signalling.

No MeSH data available.


Related in: MedlinePlus