UNC-6 (netrin) stabilizes oscillatory clustering of the UNC-40 (DCC) receptor to orient polarity.

The receptor deleted in colorectal cancer (DCC) directs dynamic polarizing activities in animals toward its extracellular ligand netrin. How DCC polarizes toward netrin is poorly understood. By performing live-cell imaging of the DCC orthologue UNC-40 during anchor cell invasion in Caenorhabditis elegans, we have found that UNC-40 clusters, recruits F-actin effectors, and generates F-actin in the absence of UNC-6 (netrin). Time-lapse analyses revealed that UNC-40 clusters assemble, disassemble, and reform at periodic intervals in different regions of the cell membrane. This oscillatory behavior indicates that UNC-40 clusters through a mechanism involving interlinked positive (formation) and negative (disassembly) feedback. We show that endogenous UNC-6 and ectopically provided UNC-6 orient and stabilize UNC-40 clustering. Furthermore, the UNC-40-binding protein MADD-2 (a TRIM family protein) promotes ligand-independent clustering and robust UNC-40 polarization toward UNC-6. Together, our data suggest that UNC-6 (netrin) directs polarized responses by stabilizing UNC-40 clustering. We propose that ligand-independent UNC-40 clustering provides a robust and adaptable mechanism to polarize toward netrin.

Ignác Goldziher's report on the books brought from the orient for the Hungarian Academy of Sciences

© The author. Published by Oxford University Press on behalf of the University of Manchester. All rights reserved.This paper contains the English translation of Ignác Goldziher's Hungarian essay Report on the Books Brought from the Orient for the Hungarian Academy of Sciences with Regard to the Conditions of the Printing Press in the Orient (1874). The introduction provides the historical and scholarly context of the article. The Arabic printed books Goldziher bought in Egypt reflect his understanding of a specialized Arabic Studies library in the 1870s. The general argument is that Goldziher connected the Arab nation and Arabic texts based on the Hungarian and German concepts of liberal nationalism. This connection instrumentalized religious texts for a non-religious goal.