Synaptic cell adhesion molecules

Question 1

What are SCAMs and what is their function

Answer 1

What: SCAMs or Synaptic Adhesion Molecules are transmembrane proteins that are located to the synapse
Function: They contribute to synaptic plasticity

Question 2

What are the 4 stages of synapse formation and what is the function?

Answer 2

Stage 1: Establishment
Function: the pre-and postsynaptic neurons are recognized by possibly the interaction between SCAMS
Stage 2: Assembly
Function:Recruitment of synaptic vesicles, active zones, and PSDs. SCAMS regulate physical cell-cell adhesion and serve as anchor proteins to cluster or recruit receptors or components of the synaptic signalling machinery
Stage 3: Specification
Function:Organisation of the molecular components of the synapse which results in the functionality of the synapse
Stage 4: Plasticity
Function:SCAMS may contribute to structural and functional synaptic plasticity in activity-dependent events.

Question 3

What are neurexins & neuroligins and what are their functions

Answer 3

What These are both SCAMs and neurexins have a large alpha and short beta isoform. The alpha forms contain 6 LNS domains and 3 interspersed EGF-like domains, while beta forms contain one single LNS domain. The 6th LNS domain of the alpha neurexins and the single LNS domain of the beta neurexin bind to neuroligin to form a trans-synaptic cell adhesion complex.
Function: This complex coordinates the recruitment of calcium channels and components of the release machinery to presynaptic active zones.

Question 4

What are examples of SCAMs

Answer 4

• Neurexin
• Neuroligings
• Ig-domain proteins – synCAMS
• Receptor phosphoserine kinases and phosphatases
• Leucine-rich repeat proteins