title: Proteome analysis of gametophores identified a metallothionein involved in various abiotic stress responses in Physcomitrella patens.
abstract: Physcomitrella patens is a model plant for studying gene function using a knockout strategy. To establish a proteome database for P. patens, we resolved over 1,500 soluble proteins from gametophore and protonema tissues by two-dimensional electrophoresis (2-DE) and obtained peptide mass fingerprints (PMFs) by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). Using expressed sequence tags (ESTs), we were able to predict the identities of 90 protein spots. Most of these were related to energy or primary metabolism. Comparative proteome analysis was used to identify proteins specific for each of the tissue types. One of these was a metallothionein type-2 (PpMT2) protein that was highly upregulated in gametophore tissue. PpMT2 was induced in both the gametophore and protonema following culture on solid media and in response to various abiotic stresses such as copper, cadmium, cold, indole-3-acetic acid, and ethylene. We suggest that PpMT2 is not only involved in metal binding and detoxification, but also in many biological aspects as a metal messenger or a protein with additional functions.
authors.affiliation: School of Life Sciences and Biotechnology, Korea University, Seoul, 136-701 Korea.
authors.forename: Sung Hyun
authors.initials: SH
authors.lastname: Cho
authors.forename: Quoc Truong
authors.initials: QT
authors.lastname: Hoang
authors.forename: Yoon Young
authors.initials: YY
authors.lastname: Kim
authors.forename: Hyun Young
authors.initials: HY
authors.lastname: Shin
authors.forename: Sung Han
authors.initials: SH
authors.lastname: Ok
authors.forename: Jung Myung
authors.initials: JM
authors.lastname: Bae
authors.forename: Jeong Sheop
authors.initials: JS
authors.lastname: Shin
mesh_terms: D000595:Amino Acid Sequence; D019068:Bryopsida / Q000378:metabolism*; D002104:Cadmium / Q000633:toxicity; D003080:Cold Temperature; D003300:Copper / Q000633:toxicity; D015180:Electrophoresis, Gel, Two-Dimensional; D005030:Ethylenes / Q000633:toxicity; D020224:Expressed Sequence Tags; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000633:toxicity; D008668:Metallothionein / Q000502:physiology*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000378:metabolism*; D020543:Proteome / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D005030:Ethylenes; D007210:Indoleacetic Acids; D010940:Plant Proteins; D020543:Proteome; D002104:Cadmium; C030737:indoleacetic acid; D003300:Copper; D008668:Metallothionein; C036216:ethylene