Rumi O-glucosylates the EGF repeats of a growing list of proteins essential in metazoan development, including Notch. Rumi is essential for Notch signaling, and Rumi dysregulation is linked to several human diseases. Despite Rumi's critical roles, it is unknown how Rumi glucosylates a serine of many but not all EGF repeats. Here we report crystal structures of Drosophila Rumi as binary and tern...

Protein O-glucosylation is a conserved post-translational modification that occurs on epidermal growth factor-like (EGF) repeats harboring the C(1)-X-S-X-P-C(2) consensus sequence. The Drosophila protein O-glucosyltransferase (Poglut) Rumi regulates Notch signaling, but the contribution of protein O-glucosylation to mammalian Notch signaling and embryonic development is not known. Here, we show...

Notch signaling is broadly used to regulate cell-fate decisions. We have identified a gene, rumi, with a temperature-sensitive Notch phenotype. At 28 degrees C-30 degrees C, rumi clones exhibit a full-blown loss of Notch signaling in all tissues tested. However, at 18 degrees C only a mild Notch phenotype is evident. In vivo analyses reveal that the target of Rumi is the extracellular domain of...

Mutations in rumi result in a temperature-sensitive loss of Notch signaling in Drosophila. Drosophila Rumi is a soluble, endoplasmic reticulum-retained protein with a CAP10 domain that functions as a protein O-glucosyltransferase. In human and mouse genomes, three potential Rumi homologues exist: one with a high degree of identity to Drosophila Rumi (52%), and two others with lower degrees of i...

The protein O-glucosyltransferase Rumi/POGLUT1 regulates Drosophila Notch signaling by adding O-glucose residues to the Notch extracellular domain. Rumi has other predicted targets including Crumbs (Crb) and Eyes shut (Eys), both of which are involved in photoreceptor development. However, whether Rumi is required for the function of Crb and Eys remains unknown. Here we report that in the absen...

UNLABELLED Haploinsufficiency for the Notch ligand JAG1 in humans results in an autosomal-dominant, multisystem disorder known as Alagille syndrome, which is characterized by a congenital cholangiopathy of variable severity. Here, we show that on a C57BL/6 background, jagged1 heterozygous mice (Jag1(+/-) ) exhibit impaired intrahepatic bile duct (IHBD) development, decreased SOX9 expression, an...

A special numeral system rumi has been in use in North Africa since the Xe century. It remained in use until the XVIIe century. This system has been especially used in the administration of the city of Fez in Morocco. It has also been used in Al-Andalusians, Spain, starting from the XIIe century. The forms of the digits are quiet di erent from the Arabic or the Arabic-Indic digits in use today....

1 Turkan Cengiz1, Fahriye Kılınç2, Hatice Isık1, Refika Selimoğlu1, Handan Yılmaz3 1Department of Obstetrics and Gynecology, Mevlana (Rumi) University Faculty of Medicine, Konya, 2Department of Pathology, Mevlana (Rumi) University Faculty of Medicine, Konya, 3Department of Obstetrics and Gynecology, Istanbul University Cerrahpasa Faculty of Medicine, Istanbul, Turkey Abnormal Uterine Bleedings ...

Notch is a key signaling protein mediating cell-fate decisions during development. In this issue, Acar et al. (2008) describe a new gene called rumi that is required for Notch signaling in Drosophila. This gene encodes an O-glucosyltransferase that attaches glucose sugars to serine residues in the multiple EGF domains of the extracellular region of Notch. This modification by Rumi likely influe...

Mutations in Drosophila rumi result in a temperature-sensitive loss of Notch signaling. Rumi is a protein O-glucosyltransferase that adds glucose to EGF repeats with a C-X-S-X-P-C consensus sequence. Eighteen of the 36 EGF repeats in the Drosophila Notch receptor contain the consensus O-glucosylation motif. However, the contribution of individual O-glucose residues on Notch to the regulation of...