CREB1 is a bZIP transcription factor that activates target genes through cAMP response elements. CREB1 is able to mediate signals from numerous physiological stimuli, resulting in regulation of a broad array of cellular responses. While CREB1 is expressed in numerous tissues, it plays a large regulatory role in the nervous system. CREB1 is believed to play a key role in promoting neuronal survival, precursor proliferation, neurite outgrowth, and neuronal differentiation in certain neuronal populations (1-3). Additionally, CREB1 signaling is involved in learning and memory in several organisms (4-6). CREB1 is able to selectively activate numerous downstream genes through interactions with different dimerization partners. CREB1 is activated by phosphorylation at Ser133 by various signaling pathways including Erk, Ca2+, and stress signaling. Some of the kinases involved in phosphorylating CREB1 at Ser133 are p90RSK, MSK, CaMKIV, and MAPKAPK-2 (7-9).