Figure 3.

D-stathmin expression and subcellular localization. (A) mRNA: northern blot analysis showing a major D-stathmin transcript of ∼2.2 kb and two minor ones of ∼3 and 4 kb in total adult Drosophila RNA. Protein: a major 32-kDa protein is the product of the in vitro transcription/translation of clone 14 ([³⁵S], left) and corresponds to a major 32-kDa protein detected in 0–24-h embryo homogenates by Western blot analysis with both anti-D-stathmin antisera (right). (B) HeLa cell homogenates overexpressing human (H-) and Drosophila (D-) stathmin-myc fusion proteins were fractionated by differential centrifugation (see MATERIALS AND METHODS): low-speed supernatant (S1); 100,000 × g supernatant (S2) and pellet (C2); 100°C supernatant (S3). Equivalent amounts of each fraction were analyzed by Western blotting with anti-myc antiserum. H- and D-stathmins (arrowheads) and endogenous c-myc (double-headed arrows) are indicated.