Protocol to identify the RNA-binding domains of RBPs in a global scale

RBDmap employs UV crosslinking, oligo(dT) selection, partial proteolysis and quantitative proteomics to identify the protein regions engaged in RNA binding in a system-wide scale. Applied to HeLa cells it reported 1,174 RNA-binding sites mapping to 529 RBPs, many of which lacking known RNA-binding domains. A detail RBDmap protocol has now been released for the community in Nature protocols


The use of RBDmap can now be extended to other cell lines or organisms and can be used to profile in a global scale the behaviour of RNA-binding domains in response to different physiological conditions and stresses.”


Identification of RNA-binding domains of RNA-binding proteins in cultured cells on a system-wide scale with RBDmap. Castello A, Frese CK, Fischer B, Järvelin AI, Horos R, Alleaume AM, Foehr S, Curk T, Krijgsveld J, Hentze MW. Nat Protoc. 2017 Dec;12(12):2447-2464. doi: 10.1038/nprot.2017.106. Epub 2017 Nov 2. PMID:  29095441

PhD position in Barcelona

Our friend, Mayka Sanchez is applying for a PhD position within the framework of an MSCA-COFUND, funded by the EU and co’funded by La Caixa. The program is called INPhINIT and the deadline for application in 2nd February 2018.

  • 3-year contract in a stimulating environment
  • Complementary training
  • Secondments at national and international organisations (Universities, Research Center and Private sector)
  • Mentor appointed by ”la Caixa” Foundation from its network of alumni, the ”la Caixa” Fellows’ Association
  • Involvement in communication and dissemination activitie

Requisites
Candidates applying for a fellowship of the programme will be evaluated accordingly to their CV, letters of reference and interview.

  • Candidates must have obtained a Master degree in the last 4 years
  • A good command of English  (B2 level required)
  • It is also mandatory not to have resided in Spain more than 12 months in the last 3 years before 29 May 2018.

Application here

The activity of TRIM25 is controlled by RNA

The E3 ubiquitin ligase TRIM25 is an antiviral factor recently discovered to bind RNA by the RNA interactome studies (Castello et al., 2012 and Kwon et al., 2013). In a recent work led by our collaborator Gracjan Michlewsky (Wellcome Centre for Cell Biology, University of Edinburgh), we dissected how this protein binds to RNA and what are the consequences of this interaction in TRIM25 function. We discovered that TRIM25 binds RNA via its PRY/SPRY domain and that the interaction with RNA enhances TRIM25 E3 ligase activity, which is necessary for its antiviral role. Using CLIP analyses we showed that TRIM25 binds G-rich sequences present in hundreds of cellular RNAs. Moreover, We discovered that TRIM25 controls the levels of a key component in the interferon response pathway, ZAP (also known as PARP13 and ZC3HAV1).


In conclusion, the E3 ligase activity of TRIM25 is controlled by RNA, breaking once more the view that proteins act on RNA and not the opposite.


Original publication:
RNA-binding activity of TRIM25 is mediated by its PRY/SPRY domain and is required for ubiquitination
Nila Roy Choudhury, Gregory Heikel, Maryia Trubitsyna, Peter Kubik, Jakub S. Nowak, Shaun Webb, Sander Granneman, Christos Spanos, Juri Rappsilber, Alfredo Castello and Gracjan Michlewski
BMC biology

Decapping host and viral RNAs

In a recent work with Yolanda Revilla’s lab (CBMSO, Madrid) published in the Journal of Virology, we investigated the role in RNA metabolism of a protein from a complex DNA virus, called African swine fever virus (ASFV). This protein exhibits high homology with cellular decapping enzymes and thus can potentially remove the cap structure from the RNA body triggering degradation.  We show that this protein interacts with viral and cellular mRNAs in infected cells. This interaction results in decreased levels of both types of transcripts, agreeing with a putative role as virus-encoded decapping activity. We propose that the degradation of RNA triggered by this protein is key to control gene expression in ASFV infected cells.

 

 

PhD position in Marseille

Our Colleague Juan Reguera, offers a PhD student position at the Viral Macromolecular Complexes Teat at the AFMB in Marseille. The aim of the project is the structural and functional characterisation of retrotrasposon integration in yeast. Interested candidates can send their CV and a motivation letter to reguera@afmb.univ-mrs.fr