Indicate whether the following statements are true or false. If false, correct the sentence. Cell surface receptors that affect transcriptional regulation when activated display much faster response times than those that cause altered protein function. In G-protein coupled receptors, a signal molecule will bind to the extracellular portion of the receptor and cause phosphorylation of a GDP molecule bound to the alpha subunit of the G-protein. Enzyme-coupled receptors are typically dimerizable, such as receptor tyrosine kinases. These RTKs are often found to be mutated in cancer, as a mutation in only one receptor can cause massive changes downstream due to the outward-branching protein cascade they control.