Lennart Philipson

The Coxsackievirus and adenovirus receptor (CAR) functions as a virus receptor, but its primary biological function is unknown. A yeast two-hybrid screen was used to identify Ligand-of-Numb protein-X (LNX) as a binding partner to the intracellular tail of CAR. LNX harbors several protein-protein interacting domains, including four PDZ domains, and was previously shown to bind to and regulate the expression level of the cell-fate determinant Numb. CAR was able to bind LNX both in vivo and ...

The coxsackie- and adenovirus receptor (CAR) is a transmembrane protein belonging to the immunoglobulin superfamily. The function of CAR as a virus receptor has been extensively analyzed, while its physiological role and expression pattern in adult tissues have remained less clear. CAR associates with epithelial tight junctions in vitro and mediates cell-cell adhesion. Using a set of affinity-purified antibodies, we show that CAR is predominantly expressed in epithelial cells lining the ...

The coxsackievirus and adenovirus receptor (CAR) is a transmembrane protein important for viral binding to target cells. Using RT-PCR, Western analysis, GST pull-down assay and indirect immunofluorescence, it was shown that CAR is expressed in male germ cells from mice, rats, and humans. CAR was detected in round spermatids in the testis as well as in purified, mature spermatozoa. The two membrane-bound isoforms of CAR occupied different subcellular sites in the acrosomal region of the ...

Anti-RNP sera were used to isolate a cDNA clone for the largest polypeptide of the U1 snRNP, a protein of mol. wt 70 kd designated 70K, from a human liver cDNA library constructed in the expression vector pEX1. The cro-beta-galactosidase-70K fusion protein reacted with various anti-RNP patient sera, a rabbit anti-70K antiserum, as well as with a monoclonal antibody specific for this protein. The sequences of four 70K peptides were determined and they match parts of the deduced amino acid ...

The mechanisms controlling early adenovirus gene expression in vivo have been studied using inhibitors of protein synthesis. When inhibitors were added shortly before or at the onset of infection, viral mRNA from all early regions was transcribed, spliced and accumulated over a 7 hr period. After longer pretreatment, accumulation of several early mRNAs were suppressed. Addition of inhibitors 1 hr after infection enhanced the accumulation of viral mRNA in the cytoplasm. Translation of ...

The subgroup C of the adenoviruses (Ad) and the group B coxsackieviruses (CVB) are structurally unrelated viruses that are known to compete for an unidentified cell surface receptor. We now describe the isolation of cDNAs from human and mouse that encode the human CVB and Ad2 and 5 receptor (HCAR) and the mouse CVB Ad2 and 5 receptor (MCAR). Both are 46-kDa glycoproteins whose primary amino acid sequences are highly homologous. Structurally, HCAR and MCAR appear to be transmembrane ...

The localization of the gene(s) mediating methicillin (mecr) in Staphylococcus aureus was determined by transformation with deoxyribonucleic acid (DNA) from a natural mecr strain (DU 4916) and transformation obtained with DNA from this strain. Streptomycin resistance genes (strr) and novobiocin resistance genes (novr) were used concurrently as representatives for chromosomal genes; penicillinase (PI254) and tetracycline plasmids were used as examples of medium- and small-size ...

A 29.5-kb plasmid, pSX267, from Staphylococcus xylosus DSM 20267 was found to code for arsenate, arsenite, and antimony (III) resistance. The isolated plasmid was transformed into S. aureus, where the same resistances were expressed. It was of special interest to see whether pSX267 showed any DNA sequence homology with the well-studied penicillinase plasmid from S. aureus pI258, also conferring arsenate, arsenite, and antimony III resistance. By the use of the Southern blotting ...

CELL growth and differentiation are usually mutually exclusive1. Transformation of myoblasts by retroviruses containing the myc oncogene inhibits differentiation, preventing cells from withdrawing from the cell cycle4,5. If cell-cycle withdrawal is a prerequisite for myoblast differentiation, it is probably an early event in terminal cell differentiation, but this has not yet been established6. MyoD1 regulates myogenesis7. It is expressed only in skeletal muscle8, but can convert other ...

With high resolution SDS-polyacrylamide gel electrophoresis (Maizel, 1971) and a new method to extract the basic proteins, it was ascertained that adenovirus type 2 contains at least 10 distinct polypeptides (II, III, IIIa, IV–X) and possibly more. Five proteins (V, VI, VII, VIII, and X) were purified by selective extraction in urea at high ionic strength, and low pH followed by preparative polyacrylamide electrophoresis toward the cathode at pH 3.4. Antisera, produced against proteins ...

Incomplete virus particles were isolated from cells infected with adenovirus type 3. More than 30% of the particles recovered at 72 hr after infection were found to be incomplete.Polyacrylamide electrophoresis revealed that incomplete particles were deficient in the two major core polypeptides, but contained enhanced levels of a polypeptide present in complete virions in only minute amounts. The amino acid composition of incomplete particles showed reduced levels of both arginine and ...

Messenger ribonucleic acid (mRNA) from cells productively infected with adenovirus type 2 was isolated by affinity chromatography on polyuridylic acid [poly (U)] bound to Sepharose. At least 90% of the polyadenylic acid [poly (A)]-containing polysomal mRNA was retained by the poly (U) Sepharose and thus separated from more than 95% of the ribosomal RNA and transfer RNA. In these experiments, 65% of the early (3 to 5 hr postinfection) and 85% of the late (14 to 16 hr postinfection) ...

In NIH3T3 fibroblasts, the ubiquitous helix-loop-helix (HLH) protein E2A (E12/E47) and the myogenic HLH proteins MyoD, MRF4 and myogenin are growth-inhibitory, while two ubiquitous Id proteins lacking the basic region are not. The dimerization domain mediates inhibition. However, in addition to the HLH region, E2A contains two inhibitory regions over-lapping with the main transcriptional activation domains. The growth-suppressive activity of the intact E47 as well as MyoD was ...