CAMSAP

CAMSAP is a protein that plays a crucial role in cell division, specifically in the regulation of the spindle assembly checkpoint (SAC). The SAC is a molecular surveillance mechanism that ensures all chromosomes are correctly attached to the spindle microtubules before the cell proceeds to divide. This prevents aneuploidy, a condition where cells have an abnormal number of chromosomes. CAMSAP, which stands for Cytoplasmic Assemlby protein with a Mitotic Associated domain, is a key component of this checkpoint.

There are three known isoforms of CAMSAP in mammals: CAMSAP1, CAMSAP2, and CAMSAP3. These proteins primarily function by binding to the plus ends of microtubules, the dynamic filaments that form the spindle. By stabilizing these microtubules and preventing their depolymerization, CAMSAP proteins help maintain the integrity of the spindle apparatus. Their localization to the kinetochores, the protein structures on chromosomes where microtubules attach, is essential for sensing tension and signaling errors in chromosome attachment.

When chromosome attachment is faulty, CAMSAP proteins contribute to the recruitment of other SAC proteins, ultimately leading to the inhibition of the anaphase-promoting complex/cyclosome (APC/C). This inhibition delays the cell cycle until the errors are corrected. CAMSAP proteins are conserved across many eukaryotes, highlighting their fundamental importance in ensuring genomic stability during cell division. Dysregulation of CAMSAP function has been implicated in various diseases, including cancer, where uncontrolled cell proliferation is a hallmark.