A cDNA sequence that encodes a 61-amino acid polypeptide precursor with homologies to proline-rich antimicrobial peptides (AMPs) was identified in the oyster Crassostrea gigas. After release of a hydrophobic signal peptide, the resulting 37-amino acid peptide, Cg-Prp, is composed of an acidic region and a cationic proline-rich region. To evaluate the biological properties of Cg-Prp, multiple pr...

Differentially expressed in ovarian cancer-2/disabled 2 (DOC-2/DAB2) protein, often lost in prostate cancer and other cancer types, is a part of homeostatic machinery in normal prostate epithelium. DOC-2/DAB2 modulates mitogen-elicited mitogen-activated protein kinase (MAPK) signal transduction by sequestering several adaptor or effector molecules, such as growth factor receptor bound protein 2...

BPGAP1 is a Rho GTPase-activating protein (RhoGAP) that regulates cell morphogenesis, cell migration, and ERK signaling by the concerted action of its proline-rich region (PRR), RhoGAP domain, and the BNIP-2 and Cdc42GAP homology (BCH) domain. Although multiple cellular targets for the PRR and RhoGAP have been identified, and their functions delineated, the mechanism by which the BCH domain reg...

Although most L-type calcium channel alpha(1C) subunits isolated from heart or brain are approximately 190-kDa proteins that lack approximately 50 kDa of the C terminus, the C-terminal domain is present in intact cells. To test the hypothesis that the C terminus is processed but remains functionally associated with the channels, expressed, full-length alpha(1C) subunits were cleaved in vitro by...

The cellular ALIX protein functions within the ESCRT pathway to facilitate intralumenal endosomal vesicle formation, the abscission stage of cytokinesis, and enveloped virus budding. Here, we report that the C-terminal proline-rich region (PRR) of ALIX folds back against the upstream domains and auto-inhibits V domain binding to viral late domains. Mutations designed to destabilize the closed c...

Neuronal cell fate decisions are directed in Drosophila by NUMB, a signaling adapter protein with two protein-protein interaction domains: a phosphotyrosine-binding domain and a proline-rich region (PRR) that functions as an SH3-binding domain. Here we show that there are at least four human NUMB isoforms and that these serve two distinct developmental functions in the neuronal lineage: differe...

BACKGROUND Because of high mutation rates, new drug-resistant viruses are rapidly evolving, thus making the necessary control of influenza virus infection difficult. METHODS We screened a constrained cysteine-rich peptide library mimicking μ-conotoxins from Conus geographus and a proline-rich peptide library mimicking lebocin 1 and 2 from Bombyx mori by using influenza virus RNA polymerase (P...

Growth factor receptor-bound protein 2 (Grb2) is a small adapter protein composed of a single SH2 domain flanked by two SH3 domains. The N-terminal SH3 (nSH3) domain of Grb2 binds a proline-rich region present in the guanine nucleotide releasing factor, son of sevenless (Sos). Using NMR relaxation dispersion and chemical shift analysis methods, we investigated the conformational change of the S...

Retroviral transmembrane proteins (TMs) contain an N-terminal fusion peptide that initiates virus-cell membrane fusion. The fusion peptide is linked to the coiled-coil core through a conserved sequence that is often rich in glycines. We investigated the functional role of the glycine-rich segment, Met-326 to Ser-337, of the human T-cell leukemia virus type 1 (HTLV-1) TM, gp21, by alanine and pr...