Clathrin and clathrin-accessory proteins in rat kidney cortex epithelia

Characterization of the EFC/F-BAR domain protein, FCHO2

We have previously shown that SGIP1α is an endocytic protein specifically expressed in neural tissues. SGIP1α has a lipid-binding domain called the MP domain, which shows no significant homology to any other domains. In this study, we characterized FCHO2, a protein with a high level of homology to SGIP1α. FCHO2 lacks the MP domain but has another lipid-binding domain, the EFC/F-BAR domain. FCHO2 was ubiquitously expressed. The FCHO2 EFC domain bound to phosphatidylserine and phosphoinositides and deformed the plasma membrane and liposomes into narrow tubes. FCHO2 localized to clathrin-coated pits at the plasma membrane and bound to Eps15, an important adaptor protein in clathrin-mediated endocytosis. FCHO2 knockdown reduced transferrin endocytosis. These results suggest that FCHO2 regulates clathrin-mediated endocytosis through its interactions with membranes and Eps15. These properties of FCHO2 are similar to those of SGIP1α. FCHO2 is likely to be a ubiquitous homologue of SGIP1α. We furthermore found that FCHO2 was subjected to monoubiquitination, and gel filtration analysis showed that FCHO2 formed an oligomer. These new properties might also contribute to the role of FCHO2 in clathrin-mediated endocytosis.

Recent progress in histochemistry

The progress in discerning the structure and function of cells and tissues in health and disease has been achieved to a large extent by the continued development of new reagents for histochemistry, the improvement of existing techniques and new imaging techniques. This review will highlight some advancements made in these fields.

The histochemistry and cell biology vade mecum: a review of 2005–2006

The procurement of new knowledge and understanding in the ever expanding discipline of cell biology continues to advance at a breakneck pace. The progress in discerning the physiology of cells and tissues in health and disease has been driven to a large extent by the continued development of new probes and imaging techniques. The recent introduction of semi-conductor quantum dots as stable, specific markers for both fluorescence light microscopy and electron microscopy, as well as a virtual treasure-trove of new fluorescent proteins, has in conjunction with newly introduced spectral imaging systems, opened vistas into the seemingly unlimited possibilities for experimental design. Although it oftentimes proves difficult to predict what the future will hold with respect to advances in disciplines such as cell biology and histochemistry, it is facile to look back on what has already occurred. In this spirit, this review will highlight some advancements made in these areas in the past 2 years.