Nucleic Acids Research, 2001, Vol. 29, No. 24 5216-5225
© 2001 Oxford University Press
The trypanosome homolog of human p32 interacts with RBP16 and stimulates its gRNA binding activity
Department of Microbiology and Witebsky Center for Microbial Pathogenesis and Immunology, SUNY Buffalo School of Medicine, 138 Farber Hall, Buffalo, NY 14214, USA
RBP16 is a guide RNA (gRNA)-binding protein that was shown through immunoprecipitation experiments to interact with 
30% of total gRNAs in Trypanosoma brucei mitochondria. To gain insight into the biochemical function of RBP16, we used affinity chromatography and immunoprecipitation to identify RBP16 protein binding partners. By these methods, RBP16 does not appear to stably interact with the core editing machinery. However, fractionation of mitochondrial extracts on MBP–RBP16 affinity columns consistently isolated proteins of 12, 16, 18 and 22 kDa that were absent from MBP control columns. We describe here our analysis of one RBP16-associated protein, p22. The predicted p22 protein has significant sequence similarity to a family of multimeric, acidic proteins that includes human p32 and Saccharomyces cerevisiae mam33p. Glutaraldehyde crosslinking of recombinant p22 identified homo-multimeric forms of the protein, further substantiating its homology to p32. We confirmed the p22–RBP16 interaction and demonstrated that the two proteins bind each other directly by ELISA utilizing recombinant p22 and RBP16. p32 family members have been reported to modulate viral and cellular pre-mRNA splicing, in some cases by perturbing interaction of their binding partners with RNA. To determine whether p22 similarly affects the gRNA binding properties of RBP16, we titrated recombinant p22 into UV crosslinking assays. These experiments revealed that p22 significantly stimulates the gRNA binding capacity of RBP16. Thus, p22 has the potential to be a regulatory factor in T.brucei mitochondrial gene expression by modulating the RNA binding properties of RBP16.
* To whom correspondence should be addressed. Tel: +1 716 829 3307; Fax: +1 716 829 2158; Email: lread{at}acsu.buffalo.edu The authors wish it to be known that, in their opinion, the first two authors should be regarded as joint First Authors
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Mahlert, C. Vogler, K. Stelter, G. Hause, and C. W. Basse The a2 mating-type-locus gene lga2 of Ustilago maydis interferes with mitochondrial dynamics and fusion, partially in dependence on a Dnm1-like fission component J. Cell Sci., July 15, 2009; 122(14): 2402 - 2412. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. L. Ammerman, J. C. Fisk, and L. K. Read gRNA/pre-mRNA annealing and RNA chaperone activities of RBP16 RNA, June 1, 2008; 14(6): 1069 - 1080. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. C. Goulah and L. K. Read Differential Effects of Arginine Methylation on RBP16 mRNA Binding, Guide RNA (gRNA) Binding, and gRNA-containing Ribonucleoprotein Complex (gRNP) Formation J. Biol. Chem., March 9, 2007; 282(10): 7181 - 7190. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. C. Goulah, M. Pelletier, and L. K. Read Arginine methylation regulates mitochondrial gene expression in Trypanosoma brucei through multiple effector proteins RNA, August 1, 2006; 12(8): 1545 - 1555. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. M. Miller, K. Halbig, J. Cruz-Reyes, and L. K. Read RBP16 stimulates trypanosome RNA editing in vitro at an early step in the editing reaction RNA, July 1, 2006; 12(7): 1292 - 1303. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Matsumoto, K. J. Tanaka, and M. Tsujimoto An Acidic Protein, YBAP1, Mediates the Release of YB-1 from mRNA and Relieves the Translational Repression Activity of YB-1 Mol. Cell. Biol., March 1, 2005; 25(5): 1779 - 1792. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. L. Penschow, D. A. Sleve, C. M. Ryan, and L. K. Read TbDSS-1, an Essential Trypanosoma brucei Exoribonuclease Homolog That Has Pleiotropic Effects on Mitochondrial RNA Metabolism Eukaryot. Cell, October 1, 2004; 3(5): 1206 - 1216. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Bortfeld, K. Auffarth, R. Kahmann, and C. W. Basse The Ustilago maydis a2 Mating-Type Locus Genes lga2 and rga2 Compromise Pathogenicity in the Absence of the Mitochondrial p32 Family Protein Mrb1 PLANT CELL, August 1, 2004; 16(8): 2233 - 2248. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Mili and S. Pinol-Roma LRP130, a Pentatricopeptide Motif Protein with a Noncanonical RNA-Binding Domain, Is Bound In Vivo to Mitochondrial and Nuclear RNAs Mol. Cell. Biol., July 15, 2003; 23(14): 4972 - 4982. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. PELLETIER and L. K. READ RBP16 is a multifunctional gene regulatory protein involved in editing and stabilization of specific mitochondrial mRNAs in Trypanosoma brucei RNA, April 1, 2003; 9(4): 457 - 468. [Abstract] [Full Text] [PDF]
|
|