Skip Navigation

Journal of Biochemistry 2006 140(1):121-133; doi:10.1093/jb/mvj136
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by Lee, J. G.
Right arrow Articles by Maeng, P. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lee, J. G.
Right arrow Articles by Maeng, P. J.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 2006 The Japanese Biochemical Society.

Regular Paper

Mutational and Functional Analysis of the Cryptic N-Terminal Targeting Signal for Both Mitochondria and Peroxisomes in Yeast Peroxisomal Citrate Synthase Cit2p

Jeong Goo Lee1,*, Yong Joo Lee1, Cheong Ho Lee2 and Pil Jae Maeng1,{dagger}

1 Department of Microbiology, School of Biological Science & Biotechnology, Chungnam National University, Daejeon 305-764; and 2 KT&G Central Research Institute, Daejeon 305-805, Korea

{dagger} To whom correspondence should be addressed. Tel: +82-42-821-6415, Fax: +82-42-821-6415, E-mail: pjmaeng{at}cnu.ac.kr

We previously found that the peroxisomal citrate synthase of Saccharomyces cerevisiae, Cit2p, contains a cryptic targeting signal for both peroxisomes (PTS) and mitochondria (MTS) within its 20–amino acid N-terminal segment [Lee et al. (2000) J. Biochem. 128, 1059–1072]. In the present study, the fine structure of the cryptic signal was scrutinized using green fluorescent protein fusions led by variants of the N-terminal segment. The minimum ranges of the cryptic signals for mitochondrial and peroxisomal targeting were shown to consist of the first 15– and 10–amino acid N-terminal segments, respectively. Substitution of the 3rd Val, 6th Leu, 7th Asn, or 8th Ser with Ala abolished the cryptic MTS function, however, no single substitution causing an obvious defect in PTS function was found. Neither the 15–amino acid N-terminal segment nor the C-terminal SKL sequence (PTS1) was necessary for Cit2p to restore the glutamate auxotrophy caused by the double {Delta}cit1 {Delta}cit2 mutation. The Cit2p variant lacking PTS1 [Cit2({Delta}SKL)p] partially restored the growth of both the {Delta}cit1 {Delta}cit2 and {Delta}cit1 mutants on acetate, while that carrying intact PTS1 or lacking the N-terminal segment [Cit2p, Cit2({Delta}N{Delta}SKL)p, and Cit2({Delta}N)p] did not. It is thus suggested that the potential of the N-terminal segment as an ambidextrous targeting signal can be unmasked by deletion of PTS1.

* Present address: Doheny Eye Institute, Univ. Southern California, 1450 San Pablo St. DVRC 203, Los Angeles, CA 90033, USA.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Mol. Biol. CellHome page
Y. J. Lee, K. L. Hoe, and P. J. Maeng
Yeast Cells Lacking the CIT1-encoded Mitochondrial Citrate Synthase Are Hypersusceptible to Heat- or Aging-induced Apoptosis
Mol. Biol. Cell, September 1, 2007; 18(9): 3556 - 3567.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.