Cloning and molecular characteristic of the metalloprotease gene LeftsH6 from tomato.
The full-length 2213-bp ftsH (filamentation temperature-sensitive H) cDNA was cloned from the cDNA library of heat-shocked tomato leaves. According to an open reading frame of 2019-bp, the deduced protein precursor was predicted to target chloroplast. The putative AAA (ATPases associated with diverse cellular activities) domain and the Zn(2+)-binding domain, characteristic of FtsH metalloproteases family, were found in the FtsH-like protein. Most similar to the FtsH6 of Arabidopsis thaliana, the tomato ftsH-like gene was named as Lycopersicon esculentum filamentation temperature-sensitive H6 (LeftsH6). Purified FtsH degraded casein but not BSA in vitro, whereas a FtsH mutant with the Glu(472) in the zinc-binding motif replaced by Gln had lost the protease activity. A single copy of LeftsH6 was detected in tomato genome by Southern blot analysis. Northern and Western blot analyses revealed consistently the heat-inducible character of the LeftsH6 gene. No LeftsH6 expression was detected after cold, salt, drought or light stress. The results provided the first experimental evidence of the existence of heat-inducible ftsH gene in higher plants.
College of Life Sciences, Shandong Normal University, Jinan 250014, China.
Ai-Qing
AQ
Sun
Jin-Ying
JY
Yang
Shu-Ying
SY
Yi
Chun-Mei
CM
Zhao
Jian
J
Liu
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000032:analysis; D004553:Electric Conductivity; D015723:Gene Library; D017343:Genes, Plant / Q000502:physiology; D018551:Solanum lycopersicum / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D045726:Metalloproteases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D016415:Sequence Alignment; D013312:Stress, Physiological / Q000235:genetics; D013696:Temperature
D018076:DNA, Complementary; D045726:Metalloproteases