"Fluorescent timer": protein that changes color with time.
We generated a mutant of the red fluorescent protein drFP583. The mutant (E5) changes its fluorescence from green to red over time. The rate of color conversion is independent of protein concentration and therefore can be used to trace time-dependent expression. We used in vivo labeling with E5 to measure expression from the heat shock-dependent promoter in Caenorhabditis elegans and from the Otx-2 promoter in developing Xenopus embryos. Thus, E5 is a "fluorescent timer" that can be used to monitor both activation and down-regulation of target promoters on the whole-organism scale.
Terskikh
A
A
School of Medicine, Stanford University, Stanford, CA 94305, USA. Alexey.Terskikh@Stanford.edu
Fradkov
A
A
Ermakova
G
G
Zaraisky
A
A
Tan
P
P
Kajava
A V
AV
Zhao
X
X
Lukyanov
S
S
Matz
M
M
Kim
S
S
Weissman
I
I
Siebert
P
P
D000818:Animals; D001921:Brain / Q000196:embryology / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics; D002460:Cell Line; D003116:Color; D005453:Fluorescence; D020869:Gene Expression Profiling / Q000379:methods*; D005786:Gene Expression Regulation; D018507:Gene Expression Regulation, Developmental; D006360:Heat-Shock Proteins / Q000235:genetics; D018398:Homeodomain Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics; D051857:Otx Transcription Factors; D011401:Promoter Regions, Genetic; D013696:Temperature; D013997:Time Factors; D015534:Trans-Activators / Q000235:genetics; D014982:Xenopus laevis / Q000196:embryology; D000097573:Red Fluorescent Protein
D006360:Heat-Shock Proteins; D018398:Homeodomain Proteins; D008164:Luminescent Proteins; D009419:Nerve Tissue Proteins; D051857:Otx Transcription Factors; D015534:Trans-Activators; D000097573:Red Fluorescent Protein