aa	Amino acid
CK	Cytokinin
CM	Catalytic module
MSP	Multistep phosphorelay system
HPt	Histidine containing phosphotransfer protein (phosphotransmitter)
RR	Response regulator
TCS	Two component system
SM	Sensory module
TM	Transmembrane region
HisKA (CAD)	HK-dimerization domain
RD, REC	Receiver domain
RLD	Receiver-like domain
PPI	Protein–protein interaction
DI	Dimerization interface
PM	Plasma membrane
ER	Endoplasmic reticulum
tZ	trans-Zeatin