A role for VAMP8/endobrevin in surface deployment of the water channel aquaporin 2.

Vesicle-associated-membrane protein 8 (VAMP8) is highly expressed in the kidney, but the exact physiological and molecular functions executed by this v-SNARE protein in nephrons remain elusive. Here, we show that the depletion of VAMP8 in mice resulted in hydronephrosis. Furthermore, the level of the vasopressin-responsive water channel aquaporin 2 (AQP2) was increased by three- to fivefold in VAMP8-null mice.

VAMP8/endobrevin as a general vesicular SNARE for regulated exocytosis of the exocrine system.

The molecular mechanism governing the regulated secretion of most exocrine tissues remains elusive, although VAMP8/endobrevin has recently been shown to be the major vesicular SNARE (v-SNARE) of zymogen granules of pancreatic exocrine acinar cells. In this article, we have characterized the role of VAMP8 in the entire exocrine system. Immunohistochemical studies showed that VAMP8 is expressed in all examined exocrine tissues such as salivary glands, lacrimal (tear) glands, sweat glands, sebaceous glands, mammary glands, and the prostate.

Mouse lymphomas caused by an intron-splicing donor site deletion of the FasL gene.

A spontaneous lymphoma was detected in mice, which was caused by a recessive autosomal mutation. The genetic basis was revealed to be a 5-bp deletion at the splicing donor site of the first intron of the FasL gene, resulting in aberrant transcripts coding for non-functional proteins. This mutation of the FasL gene caused development of lymphoma in all four mouse genetic backgrounds tested and the lymphoma was characterized by an expansion of leucocytes that were TCR+CD3+B220+CD19-CD4-CD8-.