Microtubules prepared from chick brain homogenates by successive cycles of assembly-disassembly were found to contain two high-molecular-weight proteins, designated microtubule-associated protein1 and microtubule-associated protein2. Microtubule-associated protein2 (apparent molecular weight 300,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) was the preferred substrate for an...

We report on a young boy with neurodevelopmental disorder who is carrier of novel frameshift mutation in gene MAP7D3 (MAP7 domain containing 3) Xq26.3. The protein encoded by this belongs to the MAP7 (microtubuleassociated 7) family that proposed regulate kinesin-1 (KIF5B)-dependent intracellular transport, acting as Microtubule (MT)-tethered recruitment factors and activators kinesin [1-3]. An...

In a recent issue of Molecular Cell, Papayannopoulos et al. (2005) show that N-WASP activation of actin-related protein2/3 (Arp2/3) is ultrasensitive to PI(4,5)P(2) concentration. We discuss how interactions between basic regions in proteins and negatively charged membranes can produce sharp on-off switches that may regulate biological activity.

How is dynamic instability regulated? Some microtubuleassociated proteins, or MAPs, can attach along the sides of the microtubules, slowing or reversing shrinkage. These MAPs are dominant in interphase cells and neurons, which is why microtubules in these cells are not very dynamic. Other MAPs, dominant in mitosis, attach to microtubule ends, where they can stabilize or destabilize microtubules...