Wilusz Lab
  • Home
  • What We Do
  • Publications
  • Protocols
  • Links
  • Who We Are
Hend Ibrahim

Hend Ibrahim

Post-Doctoral Fellow

Phone: 970-491-4881
Fax: 970-491-4941
Email: hibrahim@colostate.edu

Degrees

  • M.D. Doctor of Medicine with Honors: Faculty of Medicine, Zagazig University, Zagazig, EGYPT
  • M.S., Biochemistry: Department of Biochemistry and Molecular Biology, Colorado State University
  • Ph.D., Biochemistry: Department of Biochemistry and Molecular Biology, Colorado State University

Research Interests

Polyadenylation is the process by which a 3' poly(A) tail is appended to mRNAs. 3' end formation occurs co-transcriptionally and influences downstream events in mRNA metabolism including splicing, export and translation. There are two steps to polyadenylation; first the transcribing pre-mRNA must be cleaved, and the cleavage site is specified by two signals, the canonical AAUAAA which lies upstream of the cleavage site and is recognized by Cleavage Polyadenylation Specificity Factor (CPSF), and a downstream U-rich sequence which is bound by Cleavage stimulation Factor (CstF). These two entities interact and recruit the cleavage factors to the transcript. Following cleavage, the downstream portion of the RNA dissociates and CPSF along with poly(A) polymerase (PAP) promotes polyadenylation. As the poly(A) tail lengthens it is bound by the nuclear poly(A) binding proten (PABP-N1) which is involved in restricting poly(A) tail length to ~200nt.

Our lab has recently shown that the abundant nucleolar protein nucleophosmin (NPM) is deposited on mRNAs as a result of the polyadenylation process (Palaniswamy et al 2006). We believe that NPM may act as a mark for successful polyadenylation much as the exon junction complex marks mRNAs that have undergone appropriate splicing. As such, NPM has the potential to influence other events in mRNA metabolism such as splicing, mRNA export and translation. My goal is to investigate the putative role of NPM in mRNA export, splicing and polyadenylation using culture cells and in vitro assays.

Publications

Schroeder JM, Ibrahim H, Taylor L, Curthoys NP. (2006) Role of deadenylation and AUF1 binding in the pH-responsive stabilization of glutaminase mRNA. Am J Physiol Renal Physiol 290(3):F733-40.

Porter LD, Ibrahim H, Taylor L, Curthoys NP. (2002) Complexity and species variation of the kidney-type glutaminase gene. Physiol Genomics. 9(3):157-66.


Links


NPM at iHOP
http://www.ihop-net.org/UniPub/iHOP/gs/90643.html

A mammalian polyadenylation database (Poly(A) DB)
http://polya.umdnj.edu/

3' end formation at NobelPrize.org http://nobelprize.org/educational_games/medicine/dna/a/splicing/splicing_endformation.html

3' end formation at the Reactome
http://www.reactome.org/cgi-bin/eventbrowser_st_id?ST_ID=REACT_1849.1