Tomato heat stress protein Hsp16.1-CIII represents a member of a new class of nucleocytoplasmic small heat stress proteins in plants.
We describe a new class of plant small heat stress proteins (sHsps) with dominant nuclear localization (Hsp17-CIII). The corresponding proteins in tomato, Arabidopsis, and rice are encoded by unique genes containing a short intron in the beta4-encoding region of the alpha-crystallin domain (ACD). The strong nuclear localization results from a cluster of basic amino acid residues in the loop between beta5 and beta6 of the ACD. Using yeast 2-hybrid tests, analyses of native complexes of the sHsps, and immunofluorescence data, we demonstrate that, in contrast to earlier observations (Kirschner et al 2000), proteins of the sHsp classes CI, CII, and CIII interact with each other, thereby influencing oligomerization state and intracellular localization.
Siddique
Masood
M
Department of Molecular Cell Biology, Biocenter of the Goethe University, Marie-Curie-Strasse 9, D-60439 Frankfurt/M., Germany.
Port
Markus
M
Tripp
Joanna
J
Weber
Christian
C
Zielinski
Dirk
D
Calligaris
Raffaella
R
Winkelhaus
Sibylle
S
Scharf
Klaus-Dieter
KD
D000595:Amino Acid Sequence; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D020798:Two-Hybrid System Techniques
D006360:Heat-Shock Proteins