The intra-axonal transport of polypeptide H: evidence for a fifth (very slow) group of transported proteins in the retinal ganglion cells of the rabbit.

We have determined that a genetically polymorphic polypeptide (H, molecular weight approximately equal to 195,000) of the rabbit nervous system is transported down the retinal ganglion cell axons at a velocity of 0.7-1.1 mm/day. The H-polypeptide and probably at least two additional polypeptides (molecular weights approximately 145,000 and 73,000) therefore compose a group of intra-axonally transported proteins which moves more slowly than the 4 groups previously described in these neurons. The polypeptides of this fifth group are similar in molecular weight to certain polypeptides transported slowly in other mammalian neurons.