title: The transit peptide of CP29 thylakoid protein in Chlamydomonas reinhardtii is not removed but undergoes acetylation and phosphorylation.
abstract: The surface-exposed peptides were cleaved by trypsin from the photosynthetic thylakoid membranes isolated from the green alga Chlamydomonas reinhardtii. Two phosphorylated peptides, enriched from the peptide mixture and sequenced by nanospray quadrupole time-of-flight mass spectrometry, revealed overlapping sequences corresponding to the N-terminus of a nuclear-encoded chlorophyll a/b-binding protein CP29. In contrast to all known nuclear-encoded thylakoid proteins, the transit peptide in the mature algal CP29 was not removed but processed by methionine excision, N-terminal acetylation and phosphorylation on threonine 6. The importance of this phosphorylation site is proposed as the reason of the unique transit peptide retention.
authors.affiliation: Division of Cell Biology, University of Linköping, 581 85 Linköping, Sweden.
authors.forename: Maria V
authors.initials: MV
authors.lastname: Turkina
authors.forename: Arsenio
authors.initials: A
authors.lastname: Villarejo
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Vener
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D016825:Chlamydomonas reinhardtii / Q000737:chemistry*; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D045332:Photosystem II Protein Complex / Q000737:chemistry / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D020539:Sequence Analysis, Protein
chemical_list: C069660:CP29 light harvesting complex; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins; D045332:Photosystem II Protein Complex; C021261:thylakoid polypeptides