title: Sperm-specific C-terminal processing of the proteasome PSMA1/α6 subunit.
abstract: We previously reported that the ascidian sperm proteasome degrades the egg-coat protein extracellularly during fertilization. In order to explore an extracellular transport signal, we purified the proteasome from ascidian sperm and compared its subunit structure with egg and muscle proteasomes. The results showed that PSMA1/α6 subunit of the sperm proteasome is distinct from egg and muscle proteasomes. LC/MS/MS analysis revealed that the C-terminal 16 residues of sperm α6 subunit are processed. Whereas sperm-specific paralogous genes of α subunits are reported, its sperm-specific C-terminal processing is a newly discovered novel post-translational modification of the proteasome.
authors.affiliation: Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Sugashima, Toba 517-0004, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Yokota
authors.forename: Yohei
authors.initials: Y
authors.lastname: Kataoka
authors.forename: Noritaka
authors.initials: N
authors.lastname: Hashii
authors.forename: Nana
authors.initials: N
authors.lastname: Kawasaki
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sawada
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002853:Chromatography, Liquid; D008297:Male; D008969:Molecular Sequence Data; D009132:Muscles / Q000378:metabolism; D010063:Ovum / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D014561:Urochordata / Q000378:metabolism*
chemical_list: D021122:Protein Subunits; D046988:Proteasome Endopeptidase Complex