Alteration of protein subcellular location and domain formation by alternative translational initiation

Authors

  • Jun Cai,

    Corresponding author
    1. Institute of Bioinformatics, MOE Key Laboratory of Bioinformatics, Department of Automation, Tsinghua University, Beijing, China
    • Institute of Bioinformatics, MOE Key Laboratory of Bioinformatics, Department of Automation, Tsinghua University, Beijing, 100084, China
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  • Ying Huang,

    1. Institute of Bioinformatics, MOE Key Laboratory of Bioinformatics, Department of Automation, Tsinghua University, Beijing, China
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  • Fei Li,

    1. Institute of Bioinformatics, MOE Key Laboratory of Bioinformatics, Department of Automation, Tsinghua University, Beijing, China
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  • Yanda Li

    1. Institute of Bioinformatics, MOE Key Laboratory of Bioinformatics, Department of Automation, Tsinghua University, Beijing, China
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Abstract

Alternative translation is an important cellular mechanism contributing to the generation of proteins and the diversity of protein functions. Instead of studying individual cases, we systematically analyzed the alteration of protein subcellular location and domain formation by alternative translational initiation in eukaryotes. The results revealed that 85.7% of alternative translation events generated biological diversity, attributed to different subcellular localizations and distinct domain contents in alternative isoforms. Analysis of isoelectric point values revealed that most N-terminal truncated isoforms significantly lowered their isoelectric point values targeted at different subcellular localizations, whereas they had conserved domain contents the same as the full-length isoforms. Furthermore, Fisher's exact test indicated that the two ways—targeting at different cellular compartments and changing domain contents—were negatively associated. The N-term truncated isoforms should have only one way to diversify their functions distinct from the full-length ones. The peculiar consequence of subcellular relocation as well as change of domain contents reflected the very high level of biological complexity as alternative usage of initiation codons. Proteins 2006. © 2005 Wiley-Liss, Inc.

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