Kv

The royal sarcophagus Boston MFA 04.278 is of critical importance to the art historical, political and mortuary history of the early Eighteenth Dynasty, yet has been inadequately documented. This study provides new photographs and computer-generated line drawings of all decorated surfaces, new insights into alterations and recarvings, and translations of all texts. The sarcophagus, including its archaeological history and inscriptional evidence, is set in its historical context; it provides no evidence in favour of KV 20 being originally the sepulchre of Thutmose I. Descriptions of the decoration, prototype Book of the Dead texts and facial representational styles follow. Concluding remarks focus on the development of early New Kingdom sarcophagi. An appendix presents scientific analysis of the red paint and filling material used in the recarved inscriptions.

N-Glycosylation of membrane proteins is critical for their proper folding, co-assembly and subsequent matriculation through the secretory pathway. Here, we examine the kinetics of N-glycan addition to type I transmembrane KCNE1 K(+) channel β-subunits, where point mutations that prevent N-glycosylation at one consensus site give rise to disorders of the cardiac rhythm and congenital deafness. We show that KCNE1 has two distinct N-glycosylation sites: a typical co-translational site and a consensus site ∼20 residues away that unexpectedly acquires N-glycans after protein synthesis (post-translational). Mutations that ablate the co-translational site concomitantly reduce glycosylation at the post-translational site, resulting in unglycosylated KCNE1 subunits that cannot reach the cell surface with their cognate K(+) channel. This long range inhibition is highly specific for post-translational N-glycosylation because mutagenic conversion of the KCNE1 post-translational site into a co-translational site restored both monoglycosylation and anterograde trafficking. These results directly explain how a single point mutation can prevent N-glycan attachment at multiple sites, providing a new biogenic mechanism for human disease.