Cup is an eIF4E binding protein required for both the translational repression of oskar and the recruitment of Barentsz

In Drosophila oocytes, precise localization of the posterior determinant, Oskar, is required for posterior patterning. This precision is accomplished by a localization-dependent translational control mechanism that ensures translation of only correctly localized oskar transcripts. Although progress has been made in identifying localization factors and translational repressors of oskar, none of the known components of the oskar complex is required for both processes. Here, we report the identification of Cup as a novel component of the oskar RNP complex. cup is required for oskar mRNA localization and is necessary to recruit the plus end–directed microtubule transport factor Barentsz to the complex. Surprisingly, Cup is also required to repress the translation of oskar. Furthermore, eukaryotic initiation factor 4E (eIF4E) is localized within the oocyte in a cup-dependent manner and binds directly to Cup in vitro. Thus, Cup is a translational repressor of oskar that is required to assemble the oskar mRNA localization machinery. We propose that Cup coordinates localization with translation

Purification and partial sequence of the rabbit mammary gland prolactin receptor

1. 1. The prolactin receptor from rabbit mammary gland was purified to near homogeneity using a novel hydrophobic interaction Chromatographic procedure. 2. 2. Part sequencing (101 residues) revealed 34% identity with the rabbit liver growth hormone receptor, providing support for the existence of a new class of transmembrane receptors regulating growth and lactation

Growth hormone receptor and serum binding protein: purification, cloning and expression

A putative growth hormone receptor from rabbit liver and the growth hormone binding protein from rabbit serum have the same ammo-terminal amino-acid sequence, indicating that the binding protein corresponds to the extracellular hormone-binding domain of the liver receptor. The complete amino-acid sequences derived from complementary DNA clones encoding the putative human and rabbit growth hormone receptors are not similar to other known proteins, demonstrating a new class of transmembrane receptors