How does the functioning of a protein affect cell signaling?

The proteins are are present in the cells as different types of receptors. These protein receptors bonds to the signalling molecules and initiate for the physiological response. The protein receptors are present on bother sides of the cell membrane of the cells viz. extracellularly and Intracellularly hence these protein receptors check or allow the signalling molecules which can be affected by the functioning of the receptor proteins.