The Golgin GMAP210/TRIP11 Anchors IFT20 to the Golgi Complex

Eukaryotic cells often use proteins localized to the ciliary membrane to monitor the extracellular environment. The mechanism by which proteins are sorted, specifically to this subdomain of the plasma membrane, is almost completely unknown. Previously, we showed that the IFT20 subunit of the intraflagellar transport particle is localized to the Golgi complex, in addition to the cilium and centrosome, and hypothesized that the Golgi pool of IFT20 plays a role in sorting proteins to the ciliary membrane. Here, we show that IFT20 is anchored to the Golgi complex by the golgin protein GMAP210/Trip11. Mice lacking GMAP210 die at birth with a pleiotropic phenotype that includes growth restriction, ventricular septal defects of the heart, omphalocele, and lung hypoplasia. Cells lacking GMAP210 have normal Golgi structure, but IFT20 is no longer localized to this organelle. GMAP210 is not absolutely required for ciliary assembly, but cilia on GMAP210 mutant cells are shorter than normal and have reduced amounts of the membrane protein polycystin-2 localized to them. This work suggests that GMAP210 and IFT20 function together at the Golgi in the sorting or transport of proteins destined for the ciliary membrane

SHG-specificity of cellular Rootletin filaments enables naïve imaging with universal conservation

Despite growing demand for truly naïve imaging, label-free observation of cilium-related structure remains challenging, and validation of the pertinent molecules is correspondingly difficult. In this study, in retinas and cultured cells, we distinctively visualized Rootletin filaments in rootlets in the second harmonic generation (SHG) channel, integrated in custom coherent nonlinear optical microscopy (CNOM) with a simple, compact, and ultra-broadband supercontinuum light source. This SHG signal was primarily detected on rootlets of connecting cilia in the retinal photoreceptor and was validated by colocalization with anti-Rootletin staining. Transfection of cells with Rootletin fragments revealed that the SHG signal can be ascribed to filaments assembled from the R234 domain, but not to cross-striations assembled from the R123 domain. Consistent with this, Rootletin-depleted cells lacked SHG signal expected as centrosome linker. As a proof of concept, we confirmed that similar fibrous SHG was observed even in unicellular ciliates. These findings have potential for broad applications in clinical diagnosis and biophysical experiments with various organisms

A Resource-Based View of Internationalization in Emerging Economies

Chapter 2 in Impacts of Emerging Economies and Firms on International Business. One of the most remarkable phenomena of recent times is that a large number of firms from emerging economies have come to define and dominate new markets and enter the class of global innovation leaders. Firms that once specialized in cheap but high-quality substitutes (e.g. Brazil’s Embraer), or those that adopted fast second mover strategies (as the one followed by Korea’s Samsung), or firms that offered outsourcing services (for instance, India’s Wipro) are now firmly at the core of the global productivity and innovation frontier. In addition, many small and medium sized local firms that started as exporting joint ventures have moved abroad on their own account. So far, the international business literature has mostly used the eclectic ownership, location, and internalization (OLI) paradigm (Dunning, 2000) to explain the rise of emerging market multinational firms. This conceptual model examines internationalization drivers identifying motives typical for the internationalization strategic approaches of firms from emerging economies. Supplementing OLI paradigm with learning, leveraging, and linkages (LLL) framework (Mathews, 2002, 2006), which provides an understanding of how emerging economy firms create ownership advantages by integrating links with foreign partners. This integration leads to leveraging of specific assets and upgrading them by entering into new alliances and via acquisition