Zhu J K, Shi J, Bressan R A, Hasegawa P M
Center for Plant Environmental Stress Physiology, Purdue University, West Lafayette, Indiana 47907-1165.
Plant Cell. 1993 Mar;5(3):341-9. doi: 10.1105/tpc.5.3.341.
DnaJ is a 36-kD heat shock protein that functions together with Dnak (Hsp70) as a molecular chaperone in Escherichia coli. We have obtained a cDNA clone from the higher plant Atriplex nummularia that encodes a 46.6-kD polypeptide (ANJ1) with an overall 35.2% amino acid sequence identity with the E. coli DnaJ. ANJ1 has 43.4% overall sequence identity with the Saccharomyces cerevisiae cytoplasmic DnaJ homolog YDJ1/MAS5. Complementation of the yeast mas5 mutation indicated that ANJ1 is a functional homolog of YDJ1/MAS5. The presence of other DnaJ homologs in A. nummularia was demonstrated by the detection of proteins that are antigenically related to the yeast mitochondrial DnaJ homolog SCJ1 and the yeast DnaJ-related protein Sec63. Expression of the ANJ1 gene was compared with that of an A. nummularia Hsp70 gene. Expression of both ANJ1 and Hsp70 transcripts was coordinately induced by heat shock. However, noncoordinate accumulation of ANJ1 and Hsp70 mRNAs occurred during the cell growth cycle and in response to NaCl stress.
DnaJ是一种36-kD的热休克蛋白，在大肠杆菌中作为分子伴侣与Dnak（Hsp70）共同发挥作用。我们从高等植物滨藜中获得了一个cDNA克隆，它编码一种46.6-kD的多肽（ANJ1），与大肠杆菌DnaJ的氨基酸序列整体一致性为35.2%。ANJ1与酿酒酵母细胞质DnaJ同源物YDJ1/MAS5的整体序列一致性为43.4%。酵母mas5突变的互补表明ANJ1是YDJ1/MAS5的功能同源物。通过检测与酵母线粒体DnaJ同源物SCJ1和酵母DnaJ相关蛋白Sec63抗原相关的蛋白质，证明了滨藜中存在其他DnaJ同源物。将ANJ1基因的表达与滨藜Hsp70基因的表达进行了比较。ANJ1和Hsp70转录本的表达均受热激协同诱导。然而，在细胞生长周期和对NaCl胁迫的反应中，ANJ1和Hsp70 mRNA出现了非协同积累。
