Human Immunodeficiency Virus (HIV) and Simian Immunodeficiency Virus (SIV) require coreceptors to enter and infect target cells. They are dependent upon an interaction between the viral envelope glycoprotein with T cell antigen T4 (CD4) and a G protein coupled receptor (GPCR). HIV1 infection relies upon interaction with a chemokine receptor, usually chemokine (C-C) receptor 5 (CCR5). During progression of the infection, the virus tends to rely upon chemokine (C-X-C) receptor 4 (CXCR4). SIV a

This gene encodes an essential enzyme of nucleotide metabolism. The encoded protein forms a ubiquitous, homotetrameric enzyme that hydrolyzes dUTP to dUMP and pyrophosphate. This reaction serves two cellular purposes: providing a precursor (dUMP) for the synthesis of thymine nucleotides needed for DNA replication, and limiting intracellular pools of dUTP. Elevated levels of dUTP lead to increased incorporation of uracil into DNA, which induces extensive excision repair mediated by uracil glyc

The mammalian exocyst complex (sec 6/8) is a multiple protein complex essential for targeting exocytic vesicles to specific docking sites on the plasma membrane. Sec 5 is one of eight exocyst complex subunits: Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70, and Exo84. Exocyst complex regulation depends upon Sec5 binding Ral in a GTP-dependent manner. Human Sec5 maps to chromosome 6p25.3.

The covalent conjugation of ubiquitin to proteins regulates diverse cellular pathways and proteins. Ubiquitin is transferred to a target protein through a concerted action of a ubiquitin-activating enzyme (E1), a ubiquitin-conjugating enzyme (E2), such as UBE2T, and a ubiquitin ligase (E3) (Machida et al., 2006 [PubMed 16916645]).[supplied by OMIM, Mar 2008]