FIGURE 1.
Synaptic ColQ-AChE expression is post-transcriptionally regulated. QMCs were pretreated (panels B and D) or not (panels A and C) with 5.4 μm α-amanitin for 30 min followed by 10−4 m DFP in Hanks' balanced salt solution for 10 min and 3 washes. The cells were then allowed to synthesize new AChE in complete medium with (open circles) or without (solid circles) 20 μm ScVn (panels A and B) or 5 μm TTX (panels C and D) in the presence (B and D) or absence (A and C) of 5.4 μm α-amanitin for 12 h. Less than 5% of the total newly synthesized AChE is assembled into collagen-tailed A12 during this short time. The AChE forms were fractionated by velocity sedimentation in 5–20% sucrose gradients. G1, G2, G4, and A4 refer to AChE monomers, dimers, tetramers, and collagen-tailed tetramers, respectively. A12 refers to the ColQ-AChE form. The results in A and B are from a different set of cultures than the results in C and D. Neither the up-regulation of A12 in the presence of ScVn nor its down-regulation by TTX was affected by inhibiting transcription with α-amanitin.