Loss of Rab25 promotes the development of intestinal neoplasia in mice and is associated with human colorectal adenocarcinomas.

Transformation of epithelial cells is associated with loss of cell polarity, which includes alterations in cell morphology as well as changes in the complement of plasma membrane proteins. Rab proteins regulate polarized trafficking to the cell membrane and therefore represent potential regulators of this neoplastic transition. Here we have demonstrated a tumor suppressor function for Rab25 in intestinal neoplasia in both mice and humans.

N2 disease in patients with head and neck squamous cell cancer treated with chemoradiotherapy: is there a role for posttreatment neck dissection?

Objectives: To determine whether nodal necrosis and node size of 3 cm or larger are risk factors for recurrent neck disease and whether negative computed tomography-positron emission tomography (CT-PET) results 8 weeks or more after therapy indicate complete response in the neck in patients with N2 disease.

Design: Retrospective study.

Setting: State university hospital.

CB1 cannabinoid receptor activity is modulated by the cannabinoid receptor interacting protein CRIP 1a.

The CB1 cannabinoid receptor is a G-protein coupled receptor that has important physiological roles in synaptic plasticity, analgesia, appetite, and neuroprotection. We report the discovery of two structurally related CB1 cannabinoid receptor interacting proteins (CRIP1a and CRIP1b) that bind to the distal C-terminal tail of CB1. CRIP1a and CRIP1b are generated by alternative splicing of a gene located on chromosome 2 in humans, and orthologs of CRIP1a occur throughout the vertebrates, whereas CRIP1b seems to be unique to primates.

Myosin vb is associated with plasma membrane recycling systems.

Myosin Va is associated with discrete vesicle populations in a number of cell types, but little is known of the function of myosin Vb. Yeast two-hybrid screening of a rabbit parietal cell cDNA library with dominant active Rab11a (Rab11aS20V) identified myosin Vb as an interacting protein for Rab11a, a marker for plasma membrane recycling systems. The isolated clone, corresponding to the carboxyl terminal 60 kDa of the myosin Vb tail, interacted with all members of the Rab11 family (Rab11a, Rab11b, and Rab25).

Genomic structure of murine Rab11 family members.

Rab11a, Rab11b, and Rab25 in mammals are thought to comprise a subfamily of Rab proteins, although Rab25 has two amino acid differences in its effector domain. We have isolated and characterized the genomic sequences of murine Rab11a and Rab25 and compared them with those of previously characterized mammalian Rab genes. The Rab11a gene spans 29 kb and Rab25 spans 9 kb.