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Aip1p Dynamics Are Altered by the R256H Mutation in Actin
Published on: July 30, 2014
Mutational analysis of betaCOP (Sec26p) identifies an appendage domain critical for function
Carol J DeRegis1, Peter B Rahl, Gregory R Hoffman
1Graduate Program in Comparative Biomedical Sciences, Cornell University, Ithaca NY 14853, USA. cjd37@cornell.edu
BMC Cell Biology
|January 24, 2008
Summary
The betaCOP appendage domain is essential for yeast viability, mimicking adaptin structures. This suggests a conserved regulatory role for COPI vesicle coat appendages in cellular transport.
Area of Science:
- Cell Biology
- Molecular Biology
- Structural Biology
Background:
- The gammaCOP appendage domain of the COPI vesicle coat resembles adaptin-family appendages.
- The FxxxW motif is conserved in gammaCOP and betaCOP appendage domains, suggesting functional similarity.
Purpose of the Study:
- To investigate the structural and functional significance of the predicted betaCOP appendage domain.
- To explore the role of betaCOP in COPI vesicle coat function and its relationship with adaptin-family proteins.
Main Methods:
- Sequence comparisons and structural prediction tools were used to analyze the betaCOP COOH-terminus.
- Yeast genetics, including deletion and mutagenesis, were employed to assess appendage domain function.
- Suppression screening identified potential modulators of betaCOP function, such as ArfGAP Glo3p.
Main Results:
- The COOH-terminus of yeast Sec26p (betaCOP) was predicted to mimic adaptin-family appendages.
- Deletion of the betaCOP appendage domain resulted in inviability in yeast and dominant-negative effects upon overexpression.
- Mutagenesis identified critical residues within the betaCOP appendage domain, and Glo3p was identified as a modulator independent of its GAP activity.
Conclusions:
- The predicted betaCOP appendage domain is essential for yeast viability.
- Both COPI appendages (gammaCOP and betaCOP) likely play biologically active regulatory roles.
- The structural similarity to adaptin-family appendage domains suggests conserved mechanisms in vesicle trafficking.
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