Affordable Access

Fewer phosphates but fatter axons

The Journal of Cell Biology
The Rockefeller University Press
Publication Date
DOI: 10.1083/jcb1635iti1
  • In This Issue
  • Biology


Th e Jo ur na l o f C el l B io lo gy 926 The Journal of Cell Biology | Volume 163, Number 5, 2003 In This IssueIn This Issue Fewer phosphates but fatter axons xons are fattened by an unexpected neurofilament (NF) subunit, according to Garcia et al. (page 1011) and Rao et al. (page 1021), who find that more phosphorylation sites are not necessarily better when it comes to driving axon expansion. The radial growth-inducing subunit is one of three that make up NFs. The COOH-terminal tails of two of these subunits, NF-H and NF-M, extend perpendicular to the main NF axis and thus bridge NFs with adjacent NFs, actin filaments, or microtubules. These COOH-terminal tails are phosphory- lated in response to myelination, which also initiates a tenfold expansion in volume that is critical for fast conduction of action potentials. As NF-H has 51 phosphorylation sites in its COOH- terminal tail, and NF-M has just 7, NF-H was assumed to be the key phos- phorylation target in axonal expansion, with some researchers suggesting that A The APC–tumor connection hromosomal instability—the less than faithful mitotic segregation of chromosomes—is a hallmark of several cancers, particularly colorectal tumors. Also common in these tumors is a mutation that truncates the adenomatous polyposis coli (APC) protein. On page 949, Green and Kaplan show that this is more than coincidence—APC truncations lead to defective mitotic spindles resembling those of colo- rectal tumor cells. The faulty spindles are a result of defective capture of C microtubule plus ends. The authors expressed the truncated APC protein in noncancerous cell lines that also had normal APC and found that, in these cells, spindle microtubles could no longer grab hold of the kinetochores. This caused chromo- some misalignment and segregation defects. Astral microtubules were lost, presumably because they were not stabilized by interactions with the cel

There are no comments yet on this publication. Be the first to share your thoughts.


Seen <100 times