Plant transmembrane receptors: new pieces in the signaling puzzle.

The past few years have seen the mechanisms used by plants to transmit extracellular signals into the cytoplasm begin to be uncovered. Multiple plant proteins have been identified that resemble the receptor protein kinases of animal cells. These are known as receptor-like protein kinases or RLKs. Variations in structure and patterns of synthesis of different RLKs suggest that these proteins are involved in mediating a variety of cellular signaling processes, can respond to diverse extracellular signals and have different physiological functions.