Protein Domains

• Phospho-dependent Protein Interaction Domains in Signal Transduction

Intracellular signaling networks control many different aspects of cellular behavior, and are assembled through the interactions of proteins with one another, and with lipids, nucleic acids and small molecules. This design allows the internal ‘wiring’ of the cell to respond dynamically to extracellular signals, and provides flexibility so that a limited set of signaling proteins can provide distinct biological functions in different cellular contexts. For example, mammalian receptors that are important in axon guidance, and formation of the mammalian brain, can also regulate post-synaptic functions associated with learning and memory after birth. Investigating how such signaling pathways are organized is relevant not only for understanding how normal cells work, but also for appreciating the molecular basis for disease, since many human disorders result from breakdowns in signal transduction. Continue reading the introduction to protein domains and interactions.

While much of the human genome and its organization has been elucidated, the vast complexity of protein structures and their interactions remains to be deciphered. Most human proteins are composed of multiple modular interacting domains. The number of biomolecular interactions in a human cell is clearly going to be larger than the number of genes themselves.