Τίτλος:
Complexity of Hsp90 in organelle targeting
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Heat shock protein 90 (Hsp90) is an abundant and highly conserved molecular chaperone. In Arabidopsis, the Hsp90 gene family consists of seven members. Here, we report that the AtHsp90-6 gene gives rise to two mRNA populations, termed AtHsp90-6L and AtHsp90-6S due to alternative initiation of transcription. The AtHsp90-6L and AtHsp90-6S transcription start sites are located 228 nucleotides upstream and 124 nucleotides downstream of the annotated translation start site, respectively. Both transcripts are detected under normal or heat-shock conditions. The inducibility of AtHsp90-6 mRNAs by heat shock implies a potential role of both isoforms in stress management. Stable transformation experiments with fusion constructs between the N-terminal part of each AtHsp90-6 isoform and green fluorescent protein indicated import of both fusion proteins into mitochondria. In planta investigation confirmed that fusion of the AtHsp90-5 N-terminus to green fluorescent protein (GFP) did result in specific chloroplastic localization. The mechanisms of regulation for mitochondria- and plastid-localized chaperone-encoding genes are not well understood. Future work is needed to address the possible roles of harsh environmental conditions and developmental processes on fine-tuning and compartmentalization of the AtHsp90-6L, AtHsp90-6S, and AtHsp90-5 proteins in Arabidopsis. © 2008 Springer Science+Business Media B.V.
Συγγραφείς:
Prassinos, C.
Haralampidis, K.
Milioni, D.
Samakovli, D.
Krambis, K.
Hatzopoulos, P.
Περιοδικό:
Plant Molecular Biology
Λέξεις-κλειδιά:
heat shock protein 90; messenger RNA; primer DNA, alternative RNA splicing; amino acid sequence; Arabidopsis; article; cell organelle; chemistry; fluorescence microscopy; genetic transcription; genetics; metabolism; molecular genetics; nucleotide sequence; physiology; reverse transcription polymerase chain reaction; sequence homology, Alternative Splicing; Amino Acid Sequence; Arabidopsis; Base Sequence; DNA Primers; HSP90 Heat-Shock Proteins; Microscopy, Fluorescence; Molecular Sequence Data; Organelles; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sequence Homology, Amino Acid; Transcription, Genetic, Arabidopsis
DOI:
10.1007/s11103-008-9322-8
