of [3H]PGE1 and [3H]PGE2 binding (c) to BCLM membranes (r = 0.973; P * 0.001). d depicts a correlation plot of [3H]PGE2 binding to BCLM and [3H]PGE2 binding to the cloned EP3 receptor from the mouse (Kiriyama et al, 1995) (r = 0.798, P * 0.0099). Data are mean S.E.M. from three to six experiments for the BCLM.The molecular basis of receptor subtypes is very similar an example the 4 transmembrane receptors in the Nicotinic Cholinergic receptor subtype are made up of 5 subunits ranging from 420 to 550 amino acids it is a pentameric complex. These subunits exhibit sequence identities from 25% to 75% with a similar distribution of hydrophobic and hydrophilic domains. Following the recent advances in technology molecular cloning has resulted in identifying muscle nAChR subunits 1, 1, , , (Fig. 10) and the structurally related neuronal subunits 2 to 9 and 2 to 4 with the agonist site normally located on the site. The 2 to 4 subunits can assemble with the 2 to 4 subunits to generate a functional heteromeric receptor subtype, whereas the 7 to 9 subunits can generate functional homomeric receptors. Four glycine receptor subunits have been identified: three subunits and one . Figure 10. Displaying the five subunits of the nAChRIn order to demonstrate the similarity in receptor subtypes (Fig. 11) depicts a 4 transmembrane segment when 5 of these are assemble it forms a pentameric complex (Fig. 12) these five subunits that make up the nicototinic cholinoceptor have names as mentioned previously depicted in (Fig. 13). Figure 11 4 TM subunit Figure 12 Cross section of nAChR Figure 13 Pentameric nAChR As illustrated in the table different combinations of 5 subunits make up different receptor subty...
