Interactions between neurofilaments and microtubule-associated proteins: a possible mechanism for intraorganellar bridging.

Abstract

Mammalian [bovine] neurofilaments prepared from brain and spinal cord by either of 2 methods partially inhibit the in vitro assembly of microtubules. This inhibition is due to the association of a complex of high MW microtubule-associated proteins (MAP1 and MAP2) and tubulin with the neurofilament. Further analysis of the association reveals a saturable binding of purified brain MAP to purified neurofilaments with a K.delta. of 10-7 M. Purified astroglial filaments neither inhibit microtubule assembly nor show significant binding of MAP. The MAP might function as 1 element in a network of intraorganellar links in the cytoplasm.