Posttranslational modifications of alpha- and beta-tubulin in Giardia lamblia, an ancient eukaryote.
Tubulin of Giardia lamblia, a representative of the oldest eukaryotes, was screened for posttranslational modifications. Mass spectrometry of the carboxy-terminal peptides documents a large number of variants. Both alpha- and beta-tubulin show polyglycylation with up to 20 and 15 extra glycyl residues respectively. Minor variants show a low level of glutamylation without or with glycylation. The glutamylation-specific antibody GT335 detects alpha- and beta-tubulin in immunoblots. The terminal tyrosine is fully retained in alpha-tubulin, which is completely acetylated at Lys-40. Thus except for the detyrosination/tyrosination cycle all posttranslational modifications known for higher eukaryotes are already present in Giardia.
Weber
K
K
Max Planck Institute for Biophysical Chemistry, Department of Biochemistry, Göttingen, Germany.
Schneider
A
A
Westermann
S
S
Müller
N
N
Plessmann
U
U
D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D016829:Giardia lamblia / Q000737:chemistry* / Q000235:genetics; D005973:Glutamine / Q000737:chemistry; D005998:Glycine / Q000737:chemistry; D008239:Lysine / Q000737:chemistry; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism*; D014443:Tyrosine / Q000032:analysis
D010446:Peptide Fragments; D014404:Tubulin; D005973:Glutamine; D014443:Tyrosine; D008239:Lysine; D005998:Glycine