BIOL 200 Lecture Notes - Lecture 3: Catenin, Rna Polymerase Ii, Polyacrylamide Gel Electrophoresis
22 Jun 2016
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Document Summary
Translation gradient of nanos protein (concentrated posteriorly) throughout the egg as protein diffuses anteriorly from site of production o hunchback localized at anterior pole. Mrna exists throughout embryo but protein is concentrated at anterior pole. Nanos represses translation of hunchback mrna; observable in nanos mutant. Lack of repression (in nanos mutants) lethal. Post-translational regulation: protein modification o phosphorylation. Kinases activated by phosphate, transfer phosphate from one substrate to another on specific donors to hydroxyl groups on ser, tyr, thr. Can cause mobility shifts in sds-page electrophoresis; proteins migrate according to molecular mass on polyacrylamide gel because they are boiled and coated with highly negatively charged sds. Phosphorylated proteins bind reduced sds and thus proteins do not carry as large of a negative charge, leads to mobility shift. Once ctd is fully phosphorylated, clear mobility shift can be detected as protein acts with greater molecular weight.
