Cold Spring Harbor, NY Like all living things, plants depend for their growth and sustenance on elaborate signaling networks to maintain stem cells, cells that have an almost magical regenerative capacity. The signals sent through these networks convey an incredible diversity of instructions, which make it possible for plants to follow genetic and cellular programs regulating growth, shape, and energy production and consumption.
A team of plant biologists at Cold Spring Harbor Laboratory (CSHL) led by Professor David Jackson has pioneered the use of genetics to discover how plants cells communicate certain instructions from one to another via tiny channels called plasmodesmata (PD). Having previously demonstrated that a protein called KNOTTED1 (KN1) traffics selectively through these channels, the team has now discovered that proteins called chaperonins are an indispensable factor in enabling this trafficking to occur.
The scientists have also demonstrated the importance of this specific signaling pathway, showing that it is needed to maintain stem cells, and suggest it is probably conserved broadly, in diverse species. The findings appear August 26 in the journal Science.
Plasmodesmata are microscopic channels traversing plant cell walls that connect adjacent cells. This is where their resemblance to, say, pipes connecting your water tank to your shower ceases, however, because PDs are selective. Only certain signaling molecules, or molecular complexes, can enter these channels and emerge properly on the far side.
The discovery that trafficking cannot occur in a PD-mobile protein such as KN1 unless it is facilitated by chaperonins, opened the question of what the latter actually do in the process. Chaperonins are protein complexes well known to assist in the folding of newly manufactured amino-acid chains into proteins. Like intricate pieces of origami, nascent proteins become functional only if they are tw
|Contact: Peter Tarr|
Cold Spring Harbor Laboratory