Axonal transport and distribution of cyclophilin A in chicken neurones.
In the course of pulse-label studies on the axonal transport of the small, basic, actin-binding proteins--actin depolymerizing factor, cofilin and profilin--in chicken motor neurones, we observed a heavily labelled protein of M(r) 18 kDa and pI 8.2 on fluorographs of two-dimensional polyacrylamide gels. On the basis of its M(r), pI and amino acid composition, we tentatively identified it by database searching as cyclophilin A and subsequently confirmed its identity by immunostaining. Like actin and its associated proteins, cyclophilin A was transported in slow component b of axonal transport, but unlike these proteins, cyclophilin A did not copurify with actin on DNase I. It was not found amongst labelled proteins transported by fast axonal transported by fast axonal transport. Immunostaining of chicken dorsal root ganglion cells revealed that it accumulated in neurites at points of branching, varicosities and growth cones. Our results raise the possibility that cyclophilin A is important in maintaining the native folding of actin and associated proteins during transit in axons and assembly in growth cones.
Yuan
A
A
Neuroscience Centre, University of Otago Medical School, Dunedin, New Zealand.
Mills
R G
RG
Bamburg
J R
JR
Bray
J J
JJ
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001370:Axonal Transport / Q000502:physiology*; D002478:Cells, Cultured; D002645:Chickens / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D015151:Immunoblotting; D009046:Motor Neurons / Q000378:metabolism* / Q000648:ultrastructure; D016501:Neurites / Q000378:metabolism / Q000648:ultrastructure; D019696:Peptidylprolyl Isomerase / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D012584:Sciatic Nerve / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure
D000596:Amino Acids; D019696:Peptidylprolyl Isomerase