A Determinant for Directionality of Organelle Transport in Drosophila Embryos

摘要: Abstract Background: Motor-driven transport along microtubules is a primary cellular mechanism for moving and positioning organelles. Many cargoes move bidirectionally by using both minus plus end-directed motors. How such undergo controlled net unresolved. Results: Using combination of genetics, molecular biology, biophysics, we have identified Halo, novel regulator lipid droplet in early Drosophila embryos. In embryos lacking droplets, but not that other cargoes, specifically altered; minus-end directed at developmental stages when it normally plus-end directed. This reversal due to an altered balance motion the level individual organelles; without travel distances stall forces are reduced increased motion. During development, halo mRNA highly upregulated just as initiated (phase II), its levels drop precipitously shortly before becomes III). Exogenously provided Halo prevents switch phase III wild-type induces during II mutant regulation likely be general importance because genome encodes family related proteins with similar sequences, each transiently expressed distinct domains. Conclusions: We conclude acts directionality determinant embryonic first member new class regulators.