TY - JOUR
T1 - Truncation of the caspase-related subunit (Gpi8p) of Saccharomyces cerevisiae GPI transamidase
T2 - Dimerization revealed
AU - Meitzler, Jennifer L.
AU - Gray, Jeffrey J.
AU - Hendrickson, Tamara L.
N1 - Funding Information:
The authors thank Lyana Castaldo for the gift of plasmid pLRC001 and David Kim and Dylan Chivian for helpful discussions about the Robetta server. Thanks are also extended to Dr. Robert Cole, director of the Johns Hopkins University School of Medicine Mass Spectrometry Facility for MALDI training and advice. The authors would finally like to thank Dr. Doug Barrick and the Barrick Lab for the use of their JASCO J-810 spectropolarimeter and advice on CD analysis. This work was supported by National Science Foundation Grants (SGER: 0413781) and (DBI: 0500580), an award from the Pardee foundation, and an American Chemical Society PRF Type G Grant.
PY - 2007/6/1
Y1 - 2007/6/1
N2 - Eukaryotic proteins can be post-translationally modified with a glycosylphosphatidylinositol (GPI) membrane anchor. This modification reaction is catalyzed by GPI transamidase (GPI-T), a multimeric, membrane-bound enzyme. Gpi8p, an essential component of GPI-T, shares low sequence similarity with caspases and contains all or part of the enzyme's active site [U. Meyer, M. Benghezal, I. Imhof, A. Conzelmann, Biochemistry 39 (2000) 3461-3471]. Structural predictions suggest that the soluble portion of Gpi8p is divided into two domains: a caspase-like domain that contains the active site machinery and a second, smaller domain of unknown function. Based on these predictions, we evaluated a soluble truncation of Gpi8p (Gpi823-306). Dimerization was investigated due to the known proclivity of caspases to homodimerize; a Gpi823-306 homodimer was detected by native gel and confirmed by mass spectrometry and N-terminal sequencing. Mutations at the putative caspase-like dimerization interface disrupted dimer formation. When combined, these results demonstrate an organizational similarity between Gpi8p and caspases.
AB - Eukaryotic proteins can be post-translationally modified with a glycosylphosphatidylinositol (GPI) membrane anchor. This modification reaction is catalyzed by GPI transamidase (GPI-T), a multimeric, membrane-bound enzyme. Gpi8p, an essential component of GPI-T, shares low sequence similarity with caspases and contains all or part of the enzyme's active site [U. Meyer, M. Benghezal, I. Imhof, A. Conzelmann, Biochemistry 39 (2000) 3461-3471]. Structural predictions suggest that the soluble portion of Gpi8p is divided into two domains: a caspase-like domain that contains the active site machinery and a second, smaller domain of unknown function. Based on these predictions, we evaluated a soluble truncation of Gpi8p (Gpi823-306). Dimerization was investigated due to the known proclivity of caspases to homodimerize; a Gpi823-306 homodimer was detected by native gel and confirmed by mass spectrometry and N-terminal sequencing. Mutations at the putative caspase-like dimerization interface disrupted dimer formation. When combined, these results demonstrate an organizational similarity between Gpi8p and caspases.
KW - Caspases
KW - Dimerization
KW - GPI membrane anchor
KW - GPI transamidase
KW - Gpi8
KW - Homodimer
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U2 - 10.1016/j.abb.2007.03.035
DO - 10.1016/j.abb.2007.03.035
M3 - Article
C2 - 17475206
AN - SCOPUS:34248581962
SN - 0003-9861
VL - 462
SP - 83
EP - 93
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 1
ER -