Surface Plasmon Resonance Spectroscopy (SPR) Interaction Studies of the Circadian‐Controlled Tomato LHCa4*1 (CAB 11) Protein with Its Promoter

Abstract

Feedback regulation is an important biochemical mechanism which is also able to direct the circadian timing at the transcriptional level. Independent investigations highlighted a conserved ca. 10 nucleotide motif present in many circadian regulated Lhc genes. Two of such nucleotide motifs exist within 119 nucleotides of the Lhca4*1 promoter from tomato. This promoter fragment was used as a bait in a yeast one hybrid screen and interestingly a clone encoding with sequence identity to the LHCa4*1 protein was isolated as an interaction partner. The LHCa4*1 protein was heterologous expressed and binding to the 119 bp promoter fragment was demonstrated by surface plasmon resonance spectroscopy (SPR, Biacore). This result allows to postulate an autoregulatory feedback loop involved in expression of the Lhca4*1 gene.

• Light harvesting complex protein (LHCa4*1)
• Circadian regulation
• Autoregulatory feedback loop
• Yeast one hybrid screen
• Surface plasmon resonance spectroscopy (SPR)
• Tomato