Directed insulin secretion occurs at precise cortical regions with optimal ELKS content that are devoid of microtubules.

To maintain normal blood glucose levels, pancreatic beta cells secrete insulin into the bloodstream at specialized regions at the cell periphery, often called secretion hot spots. While many secretory machinery components are located all over the cell membrane, directed secretion relies on distinct cortical patches of the scaffolding protein ELKS and the microtubule (MT)-anchoring protein LL5β. However, using TIRF microscopy of intact mouse islets to precisely localize secretion events within ELKS/LL5β patches, we now show that secretion is restricted to only 5% of ELKS/LL5β patch area.

Glucose-stimulated KIF5B-driven microtubule sliding organizes microtubule networks in pancreatic beta cells.

In pancreatic islet beta cells, molecular motors use cytoskeletal polymers microtubules as tracks for intracellular transport of insulin secretory granules. Beta-cell microtubule network has a complex architecture and is non-directional, which provide insulin granules at the cell periphery for rapid secretion response, yet to avoid over-secretion and subsequent hypoglycemia. We have previously characterized a peripheral sub-membrane microtubule array, which is critical for withdrawal of excessive insulin granules from the secretion sites.

A child with cat-eye syndrome and oculo-auriculo-vertebral spectrum phenotype: A discussion around molecular cytogenetic findings.

Cat eye syndrome (CES) is a rare chromosomal disorder that may be evident at birth. A small supernumerary chromosome is present, frequently has 2 centromeres, is bisatellited, and represents an inv dup(22)(q11) in those affected. It's known that the 22q11 region is associated with disorders involving higher and lower gene dosages.

B-cell monoclonal lymphocytosis and B-cell abnormalities in the setting of familial B-cell chronic lymphocytic leukemia.

Background: Among all hematologic malignancies, B-cell chronic lymphocytic leukemia (BCLL) has the highest familial clustering (three- to sevenfold increase), strongly suggesting a genetic component to its etiology. Familial BCLL can be used as a model to study the early pathogenesis of this disease.

Methods: We examined nine kindreds from the National Cancer Institute's Familial BCLL Registry, consisting of 19 affected members with BCLL and 33 clinically unaffected first-degree relatives.