Fig. 4.

Heat shock induces mGluR1a and mGluR5a expression in stably transfected CHO-K1 cells. Cells were heated for 2 hrs at 42.5°C. (A) Cell membranes were collected at the indicated times after the treatment and mGluR1a expression was determined by Western blotting with specific anti-mGluR1a antibodies. The receptors appear on the blot as a combination of two bands corresponding to monomeric (145 kDa) and dimeric (290 kDa) forms of the mGluR1a. One μg of membrane protein was loaded into each well. (B) mGluR5a expression was measured similarly with anti-mGluR5a antibodies. (C) mGluR1a mRNA expression in transfected cells was measured by quantitative real-time PCR. The first bar (0 hrs) represents mRNA expression in control unheated cells. mGluR1a mRNA levels were measured in triplicates and normalized to the levels of mRNA for housekeeping gene (GAPDH). (D) Heat shock increases mGluR1a expression in CHO-K1 cells nearly 100-fold. Membrane proteins were isolated 24 hrs after heating and resolved by Western blotting. In order to estimate the magnitude of stimulation of the receptors expression by heat shock the dilution curve of the samples was done. Indicated amounts of membrane protein were loaded into the gel. Lane 1, membranes from control unheated CHO-K1 cells; lanes 2-5, membranes from heat shock-treated cells.