'One of the major oxysterols in the human circulation is 4 beta-hydroxycholesterol formed from cholesterol by the drug-metabolizing enzyme cytochrome P450 3A4. Deuterium-labeled 4 beta-hydroxycholesterol was injected into two healthy volunteers, and the apparent half-life was found to be 64 and 60 h, respectively. We have determined earlier the half-lives ... More
Enhanced expression, native purification, and characterization of CCR5, a principal HIV-1 coreceptor.
AuthorsMirzabekov T, Bannert N, Farzan M, Hofmann W, Kolchinsky P, Wu L, Wyatt R, Sodroski J
JournalJ Biol Chem
PubMed ID10497246
'Seven-transmembrane segment, G protein-coupled receptors (GPCRs) play important roles in many biological processes in which pharmaceutical intervention may be useful. High level expression and native purification of GPCRs are important steps in the biochemical and structural characterization of these molecules. Here, we describe enhanced mammalian cell expression and purificationof a ... More
Identification of FEZ1 as a protein that interacts with JC virus agnoprotein and microtubules: role of agnoprotein-induced dissociation of FEZ1 from microtubules in viral propagation.
AuthorsSuzuki T, Okada Y, Semba S, Orba Y, Yamanouchi S, Endo S, Tanaka S, Fujita T, Kuroda S, Nagashima K, Sawa H,
JournalJ Biol Chem
PubMed ID15843383
'The human polyomavirus JC virus (JCV) is the causative agent of a fatal demyelinating disease, progressive multifocal leukoencephalopathy, and encodes six major proteins, including agnoprotein. Agnoprotein colocalizes with microtubules in JCV-infected cells, but its function is not fully understood. We have now identified fasciculation and elongation protein zeta 1 (FEZ1) ... More
PSD-95 mediates formation of a functional homomeric Kir5.1 channel in the brain.
AuthorsTanemoto M, Fujita A, Higashi K, Kurachi Y,
JournalNeuron
PubMed ID11988170
Homomeric assembly of Kir5.1, an inward-rectifying K+ channel subunit, is believed to be nonfunctional, although the subunit exists abundantly in the brain. We show that HEK293T cells cotransfected with Kir5.1 and PSD-95 exhibit a Ba(2+)-sensitive inward-rectifying K+ current. Kir5.1 coexpressed with PSD-95 located on the plasma membrane in a clustered ... More
CrkL mediates Ras-dependent activation of the Raf/ERK pathway through the guanine nucleotide exchange factor C3G in hematopoietic cells stimulated with erythropoietin or interleukin-3.
AuthorsNosaka Y, Arai A, Miyasaka N, Miura O
JournalJ Biol Chem
PubMed ID10514505
CrkL is an SH2 and SH3 domain-containing adaptor protein implicated in pathogenesis of chronic myelogenous leukemia. Here, we demonstrate that overexpression of CrkL enhances the erythropoietin (Epo)- or interleukin (IL)-3-induced activation of Elk-1 and the c-fos gene promoter activity in 32D/EpoR-Wt cells. Moreover, the Epo-induced activation of ERK1 and ERK2 ... More
A major functional difference between the mouse and human ARF tumor suppressor proteins.
Authors Wadhwa Renu; Sugihara Takashi; Hasan Md Kamrul; Taira Kazunari; Reddel Roger R; Kaul Sunil C;
JournalJ Biol Chem
PubMed ID12145279
Suppression of tumorigenesis is considerably more stringent in the human than in the much shorter lived mouse species, and the reasons for this difference are poorly understood. We investigated functional differences in the control of the ARF (alternative reading frame) protein that acts upstream of p53 and is encoded along ... More
Overexpression of an ADP-ribosylation factor-guanine nucleotide exchange factor, BIG2, uncouples brefeldin A-induced adaptor protein-1 coat dissociation and membrane tubulation.
BIG2 is a guanine nucleotide exchange factor (GEF) for the ADP-ribosylation factor (ARF) family of small GTPases, which regulate membrane association of COPI and adaptor protein (AP)-1 coat protein complexes. A fungal metabolite, brefeldin A (BFA), inhibits ARF-GEFs and leads to redistribution of coat proteins from membranes to the cytoplasm ... More
Characterization of regions in hsMAD1 needed for binding hsMAD2. A polymorphic change in an hsMAD1 leucine zipper affects MAD1-MAD2 interaction and spindle checkpoint function.
In eukaryotes, the mitotic spindle assembly checkpoint provides a monitor for the fidelity of chromosomal segregation. In this context, the mitotic arrest deficiency protein 2 (MAD2) censors chromosomal mis-segregation by monitoring microtubule attachment/tension, a role that requires its attachment to kinetochores. Studies in yeast have shown that binding of MAD1 ... More
KRIT1, a gene mutated in cerebral cavernous malformation, encodes a microtubule-associated protein.
Authors Gunel Murat; Laurans Maxwell S H; Shin Dana; DiLuna Michael L; Voorhees Jennifer; Choate Keith; Nelson-Williams Carol; Lifton Richard P;
JournalProc Natl Acad Sci U S A
PubMed ID12140362
Mutations in Krev1 interaction trapped gene 1 (KRIT1) cause cerebral cavernous malformation, an autosomal dominant disease featuring malformation of cerebral capillaries resulting in cerebral hemorrhage, strokes, and seizures. The biological functions of KRIT1 are unknown. We have investigated KRIT1 expression in endothelial cells by using specific anti-KRIT1 antibodies. By both ... More
Characterization of Glis2, a Novel Gene Encoding a Gli-related, Kruppel-like Transcription Factor with Transactivation and Repressor Functions. ROLES IN KIDNEY DEVELOPMENT AND NEUROGENESIS.
Authors Zhang Feng; Nakanishi Gen; Kurebayashi Shogo; Yoshino Kiyoshi; Perantoni Alan; Kim Yong-Sik; Jetten Anton M;
JournalJ Biol Chem
PubMed ID11741991
In this study, we describe the characterization of a gene encoding a novel Krüppel-like protein, named Glis2. Glis2 encodes a relatively proline-rich, basic 55.8-kDa protein. Its five tandem Cys(2)-His(2) zinc finger motifs exhibit the highest homology to those of members of the Gli and Zic subfamilies of Krüppel-like proteins. Confocal ... More