How different species of the messenger RNA of human glutathione transferase A3-3 are generated
Xin Lan
Glutathione transferases (GSTs) are a group of enzymes that mainly protect the organism from the toxicity of foreign chemicals, such as chemical carcinogens and environmental pollutants.
Interestingly, among GSTs, human glutathione transferase A3-3 (hGST A3-3), appears selectively in tissues that actively synthesize steroid hormones. It can most efficiently catalyze a step of the conversion of cholesterol to two important sex hormones. Hence, hGST A3-3 may have effects on steroid biosynthesis and organ development as well as hormone-related diseases, for instance, breast and prostate cancer. Of most significance, a single hGST A3-3 gene can give rise to multiple messenger RNAs (mRNAs) sequences, and after translation, a few varieties of proteins with related properties are generated.
The results of this project will help study physiological functions of these different mRNAs of hGST A3-3. I have investigated the whole sequences of these mRNA species. Compared with the mRNA of hGST A3-3, another three mRNAs encoded from the same gene were found as the figure shows: one lacked section 3; one lacked both section 3 and 4 and had an additional 90 nucleotides in the 3’ end; one lacked both section 2 and 3 having an additional 18 nucleotides in the 5’ end. This phenomenon was caused by separation and then reconnection of different sections of its RNA transcript. Two detected proteins different from hGST A3-3 might correspond to the translation of second and third mRNAs in the figure. An agent, forskolin, involved in intracellular signaling, could affect production of these two proteins time-dependently.
Degree project in biology
Examensarbete i biologi, 30 hp, Uppsala university, fall 2008
Biology Education Centre and Department of Biochemistry and Organic Chemistry, Uppsala University
Supervisor: Françoise Raffalli-Mathieu
