Fare leptin receptor overlapping transcript Like-1 (Leprotl1) ve Cryptochrome 1 (Cry1) proteinleri arasındaki etkileşimin incelenmesi

Circadian rhythms are oscillations in the biochemical, physiological, and behavioral functions of organisms that occur with a periodicity of approximately 24 h. Circadian rhythms affect many metabolic processes in body such as sleep/wake cycle, feeding, hormone secretion and many others. Most importantly it is known that dysfunction in circadian rhythmicity leads to various metabolic and psychological diseases such as jet-lag, depression, obesity and even cancer. In mammals, circadian rhythms are maintained by autoregulatory transcriptional and translational feedback loops involving the basic helix loop helix PER-ARNT-SIM (bHLH/PAS) transcription factors BMAL1, CLOCK, and NPAS2. BMAL1 heterodimerizes with either CLOCK or NPAS2 and drive transcription through E-boxes located within the promoters of numerous target genes. Among the target genes are Period homolog (Per1-3), Cryptochrome (Cry1-2) and Rev-erbα that encode repressors of the BMAL1: CLOCK/NPAS2 transcriptional activity. After a delay, the translated PER and CRY proteins heterodimerize, translocate to the nucleus, and repress BMAL1: CLOCK/NPAS2 heterodimers. The PER and CRY heterodimers are progressively degraded, allowing the circuit to start again. This negative feedback leads to a cycle in gene expression that takes approximately 24 h to complete. Studies showed that there are other genes that may participate in this molecular mechanism to regulate circadian rhythm. For example a study with machine learning strategy involving naïve Bayesian approach showed that there are several genes might participate in clock function either as modifiers or as a core clock component. As continuation of this study we observed that there is an interaction between Leptin Receptor Overlapping Transcript Like-1 Protein (Leprotl1) and CRY1 protein. In this thesis, it is shown that both the mCRY1 and the mCRY2 interacts LEPROTL1 through the C-termini using the mammalian two-hybrid assay. This interaction is also confirmed with co-immunoprecipitation assay and Bi-molecular Fluorescence Complementation (BiFC). v LeprotL1 is a protein that has metabolic functions within organisms. It is already shown that LeprotL1 has role in leptin and growth hormone sensitivity of liver in mice, though its function in circadian rhythm is unknown. Here in, it is shown that LEPROTL1 interacts with both mCRY1 and mCRY2 and it is possible that such interaction may have a role in metabolic regulation of mammals.