Protein interaction is a biological process that involves the bonding of two or more proteins. These protein bonds are an essential part of the cellular functions of all living organisms and are often necessary for proteins to fulfill their specific functions. These cellular operations include critical processes such as DNA replication which is facilitated by complex molecular structures resulting from protein interactions. This process also forms the core of many cellular mediation and signaling functions. Protein bonds may take many forms including long-term complex bonds and short-term protein transport or protein modification relationships.
Proteins are naturally occurring compounds which consist of linear arrangements of amino acids. These compounds are part of the most basic and essential biological building blocks for all living things. These building blocks perform a myriad of critical functions at a cellular level either on their own or as parts of larger bonded protein groups. Commonly known as complexes, the bonded compounds formed by this protein interaction are responsible for a wide variety of critical cellular functions such as DNA replication, inter-cellular signaling, protein modification, and transportation. The study of the mechanics of protein bonding also constantly improves the ability of researchers to understand and combat many of the diseases which continue to plague mankind.
One of the most significant of these protein interaction functions is signal transduction. Chemical signals originating from outside a cell are often mediated or transferred to the inside via the mechanics of protein/protein complexes. These signal transfers are critical to many cellular processes and play an important role in the progression of diseases such as cancer. Some protein interaction bonds perform a transport role with one protein facilitating the movement of another from outside the cell to the nucleus. The reverse is also true in the case of nuclear pores, i.e., large protein complexes which move from the center of the cell to the outside via the effects of protein interaction.
Another of the many essential functions of protein interaction is the kinase protein modification process. This process involves the addition of several phosphate groups to one protein by another in a complex. These modified compounds also play a vital role in inter-cellular signal mediation with approximately 30 percent of all human proteins being modified by protein interaction based kinase. These are short-term interactions sometimes only taking nanoseconds to complete. Other protein bonding processes are more long term by nature with some taking several hours or even days to complete.