Very rapid induction of a cold shock protein by temperature downshift in Thermus thermophilus.
A rapid temperature downshift induces the expression of many proteins termed 'cold-induced' proteins. Although some of these proteins are known to participate in metabolism, transcription, translation and protein folding, processes that are affected by cold stress, it has not yet been identified which proteins sense the temperature downshift. Here we analyzed the mRNA expression profiles of genes induced immediately following a temperature downshift in Thermus thermophilus HB8. The cold shock protein gene ttcsp2 displayed the most rapid and drastic increase in mRNA. ttcsp2 mRNA was induced at 30s after temperature downshift, although ttCSP2 protein was first detected at 10 min. A temperature-dependent secondary structure was predicted to form in the 5'-untranslated region, including the Shine-Dalgarno sequence, of ttcsp2 mRNA. Stabilization of this secondary structure at 45 degrees C was assumed to prevent degradation of ttcsp2 mRNA and to slow translation. Thus, ttCSP2 is considered to act as a 'thermosensor' during temperature downshift through changes in its secondary structure.
Mega
Ryosuke
R
Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.
Manzoku
Miho
M
Shinkai
Akeo
A
Nakagawa
Noriko
N
Kuramitsu
Seiki
S
Masui
Ryoji
R
D020121:5' Untranslated Regions / Q000235:genetics; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D003080:Cold Temperature; D015964:Gene Expression Regulation, Bacterial; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D016963:Thermus thermophilus / Q000235:genetics*; D014158:Transcription, Genetic
D020121:5' Untranslated Regions; D001426:Bacterial Proteins; D012333:RNA, Messenger