2011 YÜksek lisans tez özetleri

Investigation of the relationship between glucose repression and oxidative stress response on genome-wide in Schizosaccharomyces pombe

Glucose, as a simple sugar, is preferred as a carbon and energy source by many organisms, and is also a signalling molecule. Eukaryotic organisms have a large number of complex ways and various regulatory mechanisms which play a role in glucose sensing and signalling. Processes like metabolic adaptation, glucose sensing and signalling, play important roles responding to a number of cellular and environmental stress. In this regard, studies which aim to elucidate the relationship between oxidative stress and glucose repression are increasing.

In this study, differential display technique was used to determine the gene or genes which play roles in the relationship between oxidative stress and glucose repression in S. pombe. For that purpose, constitutive invertase mutant ird11h^- which is resistant to glucose repression is used in comparison to wild type (972h^-). Total RNA was isolated from wild type and mutant cells and cDNAs were synthesized from total RNAs by using oligo-dTs. PCR products were obtained from these cDNAs by using a combination of random/oligo-dT primers. By running these products on a polyacrylamide gel, differentially expressed genes were detected. Subsequently, a second PCR was performed, checked and sequenced. The mpg1 gene encoding mannose-1-phosphate guanyltransferase enzyme and rpl302 gene encoding 60S ribosomal subunit protein L3 were obtained by BLAST analysis of the sequenced cDNAs in S. pombe genome database. In conclusion, the gene profiles obtained by differential display method were checked by Real-Time PCR.

It was indicated that the expression level of rpl302 gene, involved in general gene expression, were sharply reduced (0,6 and 0,5, respectively) in both cells (ird11 and wild type) under stressed conditions, whereas expression of mpg1 gene did not appear to cause significant change. Under non-stressed condition, rpl302 expression in ird11 was found to be increased 1,8 fold compared to that of wild type. Similarly, the expression level of mpg1 gene in ird11 was found to be statistically higher (1,3 times) than that of wild type. These findings are thought that both of two genes might be played a role in the oxidative stress tolerance in ird11. Moreover, they are supported that glucose repression to constitutive invertase mutant, ird11 would be a convenient model cell for the studies on the glucose sensing/signalling and the oxidative stress response pathways.

ÖZTÜRK Didem

Danışman : Prof. Dr. Şule Arı

Anabilim Dalı : Moleküler Biyoloji ve Genetik

Mezuniyet Yılı : 2011

Tez Savunma Jürisi : Prof. Dr. Şule ARI

Prof. Dr. Avni KURU

Prof. Dr. Nermin GÖZÜKIRMIZI

Prof. Dr. Keriman GÜNAYDIN

Yrd. Doç. Dr. Yelda ÖZDEN TOKATLI