This region is found at the N terminal of CLIP-associated proteins (CLASPs). CLASPs are widely conserved microtubule plus-end-tracking proteins that regulate the stability of dynamic microtubules [1][2]. In yeast, Drosophila, and Xenopus, a single CLASP orthologue is present. In mammals, a second paralogue (CLASP2) exists which has some functional overlap with CLASP1 [2].

1: S. pombe CLASP needs dynein, not EB1 or CLIP170, to induce microtubule instability and slows polymerization rates at cell tips in a dynein-dependent manner. Grallert A, Beuter C, Craven RA, Bagley S, Wilks D, Fleig U, Hagan IM; Genes Dev. 2006;20:2421-2436. PMID:16951255

2: Mammalian CLASP1 and CLASP2 cooperate to ensure mitotic fidelity by regulating spindle and kinetochore function. Pereira AL, Pereira AJ, Maia AR, Drabek K, Sayas CL, Hergert PJ, Lince-Faria M, Matos I, Duque C, Stepanova T, Rieder CL, Earnshaw WC, Galjart N, Maiato H; Mol Biol Cell. 2006;17:4526-4542. PMID:16914514