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Identification of the motility-related protein (MRP-1), recognized by monoclonal antibody M31-15, which inhibits cell motility.

A murine monoclonal antibody (M31-15) was identified using the penetration-inhibiting assay of a human lung adenocarcinoma cell line (MAC10) and remarkably inhibited the phagokinetic tract motility of various cancer cell lines. The antigen, motility-related protein (MRP-1), recognized by M31-15, was 25- and 28-kD proteins, and M31-15 was used to isolate a cDNA clone from a human breast carcinoma cDNA library. Sequence analysis revealed that MRP-1 had strong similarity with a B cell surface antigen (CD37), a melanoma-associated antigen (ME491), the target of an antiproliferative antibody (TAPA-1), a human tumor-associated antigen (CO-029), and the Sm23 antigen of the trematode parasite Schistosoma mansoni.

Adenocarcinoma

Debrisoquine 4-hydroxylase: characterization of a new P450 gene subfamily, regulation, chromosomal mapping, and molecular analysis of the DA rat polymorphism.

Debrisoquine 4-hydroxylase (P450db1) was purified from rat liver microsomes. Polyclonal antibody was produced and, in conjunction with immunoblots, was used to identify and purify a second immunorelated P450 (P450db2) that does not have debrisoquine hydroxylating activity. The cDNA clones to db1 and db2 were isolated from a lambda gt11 expression library, sequenced, and found to share 78% nucleotide and 73% deduced amino acid similarities. These similarities are evenly dispersed along the sequence except for a region of 190 nucleotides with 99% similarity near the carboxyl terminus of the protein-coding region; this similarity is probably the remnant of a gene conversion event. Both proteins share between 38% and 43% amino acid similarity with P450a, P450b, P450e, P450f, P450PB1, and P450j; these data indicate that P450db1 and P450db2 are members of a separate subfamily within the P450II gene family. Southern blot analysis and preliminary genomic cloning suggest that at least four genes exist in the subfamily, although the present evidence suggests that only db1 and db2 are expressed in rat liver. With the use of 19 mouse X hamster somatic cell hybrids, the db1 and db2 genes were localized to mouse chromosome 15 (P450-2D locus). A polymorphism has been described for debrisoquine metabolism in the DA rat strain, adult females having markedly decreased debrisoquine 4-hydroxylase activity. Our immunoblot analysis and mRNA analysis suggest that debrisoquine 4-hydroxylase deficiency in the female DA rat is not due to a decrease in db1 protein or mRNA. The db1 and db2 proteins are differentially regulated: during development db2 is present at birth while db1 is absent, and db1 increases by 1 week of age; in addition, db1 is slightly induced by phenobarbital, 3-methyl-cholanthrene, and dexamethasone whereas db2 is marginally increased by these latter two agents. These results demonstrate that debrisoquine 4-hydroxylase is a member of a new constitutively expressed P450II sub-family containing two or more genes in the rat and establish that the debrisoquine polymorphism in the DA rat is probably due to a structurally altered db1 protein.

Amino Acid Sequence

Molecular cloning of a novel bone-forming compound: osteoinductive factor.

cDNA clones encoding osteoinductive factor (OIF) have been isolated from a bovine osteoblast library. Sequence analysis of these clones indicated that the 105-amino-acid OIF is synthesized as a larger 299-amino-acid precursor, the carboxyl terminus of which is cleaved to yield the mature protein. Northern blot analysis of bovine osteoblast mRNA revealed two OIF-specific transcripts of 1.9 and 2.4 kb. The polymerase chain reaction was used to obtain clones coding for human OIF from the osteosarcoma cell line, MG-63. The human OIF cDNA encodes a precursor of 298 amino acids that exhibits 94% identity to the bovine protein. Northern blot analysis of various cell lines and tissues indicated that expression of OIF transcripts is limited and may be restricted to cells of bone lineage.

Amino Acid Sequence

Methods to define and locate patterns of motifs in sequences.

A method to define and search for complex patterns of motifs in nucleic acid and protein sequences is described. With this method nucleic acid motifs can be defined in eight different ways and protein motifs in six. A pattern is defined by a list of motifs. The motifs in a list are combined using the logical operators AND, OR and NOT. The list also defines the ranges of allowed separations of the motifs in the pattern. Programs to search for patterns in individual sequences and libraries of sequences are described. Patterns are defined by users and stored as annotated disk files. Hence the programming to define and locate new structures can be performed by users and fewer specific novel algorithms should be required. Examples are given of searches for transcription initiation regions, nematode mitochondrial tRNA genes and for members of the globin sequence family.

Algorithms

Discovery of Respiratory Pathogens in People Living With HIV in the African Cohort Study.

INTRODUCTION: Respiratory infection outbreaks pose a threat to the readiness of the United States and allied armed forces. Predicting and preventing such outbreaks requires understanding of the epidemiology of potential respiratory pathogens in communities where service members live and work. We conducted pan-viral surveillance of respiratory specimens from people living with HIV or without HIV but under the risk enrolled in the U.S. Military HIV Research Program's African Cohort Study to determine the prevalence and possible clinical presentation of viruses in this population. METHODS: The African Cohort Study is an open-ended prospective cohort study that enrolls people with and without HIV aged ≥15 years at 12 clinical sites in Kenya, Tanzania, Uganda, and Nigeria. The study follows participants every 6 months and collects social, demographic, clinical, and laboratory data. A total of 131 respiratory samples, collected from March 2022 to February 2023 from participants in South Rift Valley Province, Kenya, who had symptoms of respiratory illness or a positive COVID-19 test, were analyzed using a pan-viral hybridization metagenomic next-generation sequencing approach. Libraries were sequenced on the Illumina Next-generation Sequencing System NovaSeq 6000. Sample data were run through several pathogen discovery pipelines. RESULTS: Full genome and partial genome sequences were assembled for several respiratory viruses including SARS-CoV-2, human coronavirus HKU1, human adenovirus 62, human metapneumovirus, human mastadenovirus B (coinfection with SARS-CoV-2), human mastadenovirus C (coinfection with SARS-CoV-2), and human parechovirus 3 (coinfection with adenovirus 62). The results showed that SARS-CoV-2 lineages correspond with lineages circulating during March 2022 to February 2023 and revealed additional viral respiratory pathogens and viruses known to be associated with HIV. CONCLUSIONS: These preliminary results suggest that continued genomic surveillance efforts are needed for data-driven decisions on force health protection, prevention of emerging respiratory infections, and mitigation of impacts on military readiness caused by infectious diseases.

Humans

Identification of a novel murine IAP-promoted placenta-expressed gene.

We have cloned and characterized a novel cellular gene that is promoted by an intracisternal A-particle (IAP) LTR and expressed in the mouse placenta (mouse IAP promoted placental gene, MIPP). A 1067bp cDNA clone containing an IAP LTR U5 region duplicated in its 5' terminus and an ORF coding for a potential 202 amino acids protein was isolated from an 8.5 day old mouse embryo cDNA library. Sequence analysis of the 5' region of a genomic clone revealed the presence of a solo IAP LTR with the same U5 duplication, and primer extension analysis confirmed that transcription of the MIPP gene is under the control of the IAP LTR. Expression of the MIPP gene parallels that of IAP genes in normal mouse tissues with abundant transcripts present in the placenta and also in the myeloma MOPC-315. The MIPP-encoded protein is composed of four 48-amino acid repeat units and shares homology with a vaccinia virus gene product. MIPP-related sequences were also detected in higher eukaryotic genomes including human.

Amino Acid Sequence

Cloning of an interferon-gamma regulated human melanoma-associated antigen: identity to the intercellular adhesion molecule ICAM-1.

The human melanoma-associated antigen identified by the monoclonal antibody (mAb) Me14-D12 is a cell surface protein whose expression is induced by interferon-gamma (IFN-gamma). We have recently reported the molecular cloning of a genomic probe specific for the gene and mRNA of this protein. By screening with the genomic probe, we have now isolated a full length 3.0 kb cDNA from a Raji cell line-derived lambda-gt10 library. Sequence analysis of this cDNA showed a 99.8% homology with the intercellular adhesion molecule-1 (ICAM-1). Mouse Ltk- cells stably transfected with the human cDNA clone were found to express the ICAM-1 antigenic determinants detected by mAb Me14-D12 and a reference anti-ICAM-1 mAb, as judged by surface immunofluorescence. Immunoprecipitation of surface-iodinated proteins with mAb Me14-D12 revealed the presence of a 90 kD molecule with identical mobility to ICAM-1. In addition, mAb Me14-D12 could inhibit the phorbolester-stimulated aggregation of U937 cells. The findings show that the human melanoma-associated Me14-D12 antigen is the adhesion molecule ICAM-1.

Antibodies, Monoclonal

Structure and function of bicistronic RNA encoding the phosphoprotein and matrix protein of measles virus.

Two independent full-length replicas of a bicistronic RNA species containing the complete P and M genes of measles virus arranged in tandem were isolated from an expressible cDNA library. Sequences at the 5' and 3' termini suggested that the bicistronic RNA was initiated and terminated at precisely the same locations as the monocistronic mRNAs of the P and M genes, respectively. The P and M cistrons were fused together via an intergenic region which was exactly colinear with and complementary to the intergenic region of the genomic RNA. This RNA species was polyadenylated at the normal polyadenylation site at the 3' terminus of the M cistron, but not in the intergenic region. By DNA-mediated gene transfer, these cDNA clones were expressed into bicistronic RNA containing both P and M sequences in primate cells. RNA thus generated did not undergo nucleolytic processing but was translated into high levels of a 70,000-Mr protein immunoprecipitated by monoclonal antiserum against the measles virus P protein. M protein was not produced in the same cells even though the M cistron could direct M protein synthesis in vitro once excised from the upstream P cistron. These results suggested that bicistronic RNA could direct protein synthesis from the first but not the second cistron and might contribute at least in part to expression of viral genes in vivo.

Base Sequence

An alternatively processed mRNA from the avian c-erbB gene encodes a soluble, truncated form of the receptor that can block ligand-dependent transformation.

At least four major transcripts are produced by the avian c-erbB/epidermal growth factor receptor gene. cDNAs corresponding to the smallest one, a 2.6-kb transcript, were isolated from an adult chicken liver cDNA library. Sequence analysis revealed that the 3' end of one cDNA clone diverged from the known sequence of the extracellular ligand-binding domain (LBD) of the full-length receptor. A genomic DNA subfragment that contained this unique 3' divergent end was isolated. Sequence analysis of this genomic DNA fragment revealed that the 2.6-kb c-erbB transcript is produced by alternative processing. Translation of this 2.6-kb transcript would produce a secreted, truncated receptor molecule which contains the amino-terminal three-fourths of the extracellular LBD of the native receptor. COS1 cells and primary chicken embryo fibroblast cells were transfected with expression vectors that contained the 2.6-kb c-erbB cDNA. Conditioned medium from these transfected cells contained a 70-kDa protein that was specifically immunoprecipitated by a polyclonal antiserum directed against the LBD of the avian c-erbB gene product. The 70-kDa truncated receptor could be coimmunoprecipitated from conditioned medium of transfected COS1 cells that was supplemented with recombinant human transforming growth factor alpha (TGF alpha) by a monoclonal antibody against human TGF alpha. Additionally, transfected chicken embryo fibroblast cells that overexpressed the 70-kDa truncated receptor were blocked in their ability to form TGF alpha-dependent colonies in soft agar. These data suggest that the secreted, truncated receptor encoded by the 2.6-kb c-erbB transcript can bind to TGF alpha and may play an important growth-regulatory function in vitro.

Amino Acid Sequence

Characterization of the short isoform of the growth hormone receptor synthesized by rat adipocytes.

Two mRNA transcripts that are believed to be alternately spliced products of the GH receptor gene have been reported in a variety of rat tissues. The smaller (1.2 kilobases) transcript was cloned from an adipocyte library, sequenced, and found to encode a protein identical to the soluble GH-binding protein (GHBP) in plasma. An assay that is specific for the short isoform of the GH receptor, often referred to as the GHBP, has been developed using a rabbit antiserum that recognizes the unique amino acid sequence at its carboxyl end. The assay depends upon immunoprecipitation of a complex consisting of [125I]human GH, the binding protein, antiserum, and protein-A cross-linked to agarose beads. To validate the assay, samples of rat plasma were analyzed and found to contain sufficient binding protein to bind 1.46 pmol (32 ng) GH/ml, with an affinity of 2.7 x 10(9) M-1. In adipocyte extracts, binding protein activity was sufficient to bind 61 fmol GH/g tissue, with an affinity of 2.3 x 10(9) M-1. The binding protein was found primarily in the particulate fraction of adipocytes, and it is estimated that adipocytes contain approximately 7000 copies of the binding protein/cell. Only 10% of the binding activity was present in the high speed supernatant of adipocyte homogenates, and soluble binding protein did not appear to be released into the incubation medium when adipocytes were incubated in vitro. A 50-kilodalton (kDa) 35S-labeled protein that may be a glycosylated form of the binding protein was immunoprecipitated from both the soluble and particulate fractions of adipocyte extracts by the antiserum, and addition of the synthetic peptide antigen blocked immunoprecipitation of this protein. A 150-kDa protein in the high speed supernatant fraction was also specifically immunoprecipitated by the antiserum. Although it is unlikely to be a glycosylated form of the binding protein, it may cross-react with the antiserum or perhaps be coprecipitated, because it interacts with the binding protein. In addition, 38- and 42-kDa bands were specifically immunoprecipitated from the detergent-treated particulate fraction of adipocyte extracts that were enriched for the binding protein by adsorption to immobilized GH. We conclude that 1) adipocytes synthesize the short isoform of the GH receptor, and that this protein is primarily associated with a membrane fraction of the cells; and 2) the GHBP expressed in adipocytes is not released into the incubation medium and differs in size from the GHBPs in rat plasma.(ABSTRACT TRUNCATED AT 400 WORDS)

Adipose Tissue

Uncovering the diagnostic potential of seminal fluid beyond fertility: cfDNA methylation analysis for the detection of clinically significant prostate cancer.

Research on the potential use of seminal fluid as a liquid biopsy for prostate cancer detection has been limited due to challenges associated with acquisition of this bodily fluid in clinical studies. Here we sought to expand on our previous analysis, which demonstrated high levels of prostate-derived cell free DNA (cfDNA) in seminal fluid in presumed healthy individuals, to a much larger cohort that included participants with prostate cancer. A total of 279 men scheduled for prostate biopsy were enrolled over 4 months across 12 sites. Prior to their biopsy, participants mailed a seminal fluid sample collected at home to the laboratory, from which cfDNA was extracted and underwent methylation analysis. Consistent with our earlier study in healthy individuals, we observed an abundance of high molecular weight (HMW) cfDNA in all samples. Tissue-of-origin deconvolution revealed that granulocytes and sperm were the principal contributors to seminal fluid cfDNA, while prostate-derived cfDNA was present at abundances readily detectable with current technologies. The nucleosomal fraction was very pronounced in some but not all samples and was determined to be correlated with the relative sperm signal. The sperm signal was also observed to be associated with an increase in small insert sizes (< 125 bp) in the sequenced libraries. Unsupervised clustering revealed two distinct populations driven by the abundance of sperm and granulocytes. Since summarizing at the genomic region level confounded tissues of different origins, fragment-level DNA methylation features were used to characterize and quantify the prostate cancer related signal, and features associated with clinically significant prostate cancer were identified. This study expands on our previous work to further characterize seminal fluid and highlights its potential as a promising liquid biopsy medium for the detection and monitoring of clinically significant prostate cancer.

Humans

Molecular cloning and expression of human trophoblast antigen FDO161G and its identification as 3 beta-hydroxy-5-ene steroid dehydrogenase.

The monoclonal antibody FDO161G reacts with a 43-kDa protein found in human extravillous trophoblast, syncytiotrophoblast, adrenal cortex, interstitial cells of the testis and ovarian follicle cumulus cells. cDNAs for this protein have been isolated from the lambda gt11 library, sequenced, and expressed in COS-7 cells. The protein was identified as 3 beta-hydroxy-5-ene steroid dehydrogenase (HSD). The sequence of the HSD protein raises questions about its association with cell membrane systems. The lack of reactivity of FDO161G with other tissues suggests that HSD has a limited tissue distribution and that other enzymes may exist in peripheral tissues, which can convert delta 5 3-hydroxysteroids to delta 4 3-ketosteroids.

3-Hydroxysteroid Dehydrogenases

Characterization of multiple cathepsin B mRNAs in murine B16a melanoma.

We have previously shown that the highly metastatic murine B16a melanoma expresses a high level of cathepsin B mRNA which is associated with three transcripts of 2.2, 4.0 and 5.0 kb, while in contrast only a single 2.2 kb cathepsin B RNA was detected in normal murine tissues. Using recombinant DNA techniques, cDNAs corresponding to these three transcripts have been isolated from a B16a melanoma cDNA library. Sequence analysis indicates that all three mRNA transcripts contain identical coding sequences for normal preprocathepsin B. However, the 4.0 and 5.0 kb transcripts contain unusually long extended 3' untranslated regions. These results suggest that the post-transcriptional processing pathway of the cathepsin B gene is modified in B16 melanomas. The results also indicate that the increased extracellular secretion of larger forms of cathepsin B by tumors is most likely due to post-translational mechanisms and does not involve alternative splicing or a coding mutation in the gene.

Amino Acid Sequence

A gene specifying subunit VIII of human cytochrome c oxidase is localized to chromosome 11 and is expressed in both muscle and non-muscle tissues.

Subunit VIII of mammalian cytochrome c oxidase (COX; EC 1.9.3.1) exists in at least two isoforms, because different but related polypeptides have been identified in COX isolated from liver and heart of both beef and pig. We have isolated a full length cDNA specifying subunit VIII of human COX from a human liver cDNA library. Sequences hybridizing to this cDNA are present at only one site, the COX8 locus, on human chromosome 11q12-q13. The deduced human polypeptide is 58% identical with COX VIII isolated from beef liver, but only 38% identical with COX VIII isolated from beef heart. Transcriptional analysis shows that an mRNA identical with the isolated cDNA is present in abundant amounts not only in human and monkey liver tissue, but in heart and skeletal muscle as well, tissues not known previously to contain this isoform. Since the only COX VIII subunit found in human heart agrees 100% with the polypeptide deduced from this coxVIII cDNA, it may well be that, in distinction to other mammals, only one form of COX VIII exists in primates.

Amino Acid Sequence

Osteogenesis imperfecta type IV. Detection of a point mutation in one alpha 1(I) collagen allele (COL1A1) by RNA/RNA hybrid analysis.

We have identified a point mutation in one alpha 1(I) collagen allele (COL1A1) of a child with the type IV osteogenesis imperfecta phenotype. When compared to parental and control samples, skin fibroblasts of the proband synthesized two populations of type I collagen molecules. One population was normal; the other was delayed in secretion and electrophoretic migration due to post-translational overmodification. Two-dimensional gel electrophoresis of the CNBr peptides demonstrated a gradient of overmodification beginning near the carboxyl-terminal CB peptides. This predicts that the mutation delaying helix formation is near the carboxyl-terminal end of one of the component chains of type I collagen. The mRNA of the patient was probed with overlapping antisense riboprobes to type I collagen cDNA. Cleavage of a mismatch in RNA/RNA hybrids of RNase A allowed the location of the mutation to a 225-base pair region of alpha 1(I) cDNA. The mismatch was not present in RNA/RNA hybrids from either parent. This region of both alpha 1(I) alleles of the patient was isolated by screening a lambda ZAP cDNA library. Sequence determination of both alleles demonstrated a single nucleotide change, G----A, resulting in the substitution of a serine for a glycine at amino acid residue 832. This point mutation occurs in the coding region for alpha 1(I) CB6 and is concordant with the protein data. The finding of a glycine substitution in an alpha 1(I) chain of a patient with the milder type IV osteogenesis imperfecta phenotype requires modification of current molecular models for types II and IV osteogenesis imperfecta.

Alleles

Cloning and analysis of cDNA clones for rat kidney alpha-spectrin.

We have isolated a 3922-base pair (bp) cDNA clone for rat nonerythroid alpha-spectrin from a rat kidney lambda gt11 cDNA library. Sequence analysis revealed that this cDNA contains an open reading frame of 3090 bp encoding for the C-terminal 1030 amino acid sequence of rat kidney alpha-spectrin. The 3'-untranslated region (including a 38-bp poly(A+) tail) contains an 832-bp sequence. A single mRNA of about 8 kilobase pairs was detected in rat liver, kidney, brain, heart, intestine, lung, testis, stomach, spleen, and muscle with varying abundances, which is consistent with and further confirms the presence of spectrins in nonerythroid tissues as demonstrated previously by immunoblot analysis. Southern blot analysis suggested that there is a single gene for nonerythroid alpha-spectrin. The derived amino acid sequence contains sequence from the spectrin 106-residue internal repeat 12 to the C terminus of rat kidney alpha-spectrin. Sequence comparison with human and chicken nonerythroid alpha-spectrin showed that nonerythroid alpha-spectrin is well conserved during evolution. The rat kidney alpha-spectrin sequence, when compared to rat brain alpha-spectrin, contains an extra 76-amino-acid sequence at the C terminus. Sequence comparison of all the internal repeats available revealed that the internal repeat 3, 4, 5, 6, 7, and 8 has highest sequence similarity with internal repeat 12, 13, 14, 15, 16, and 17, respectively. Therefore, internal repeats 3-8 and 12-17 are most likely derived from an ancestral gene through gene duplication, suggesting that the spectrin gene is derived from a half-spectrin gene by gene duplication and divergence during evolution.

Amino Acid Sequence

Cross-resistance and glutathione-S-transferase-pi levels among four human melanoma cell lines selected for alkylating agent resistance.

A panel of four cell sublines, each selected for resistance to a different antineoplastic agent, has been developed from a human malignant melanoma cell line G3361. Following repeated exposure to escalating doses of the drug of interest, cloned sublines were developed that are 9-fold resistant to cisplatin (G3361/CP), 11-fold resistant to 4-hydroxyperoxy-cyclophosphamide (4-HC) (G3361/HC), 4-fold resistant to carmustine (BCNU) (G3361/BCNU), and 4-fold resistant to melphalan (G3361/PAM). The cross-resistance of each resistant cell line was determined for cisplatin, BCNU, 4-HC, melphalan, carboplatin, nitrogen mustard, and Adriamycin. In general, the alkylating agent-resistant cell lines were specifically resistant to the drug used for selection with the exception of the G3361/CP line, which was greater than 10-fold resistant to the cisplatin analogue carboplatin, 4-fold resistant to 4-HC, and slightly (1.5-fold) resistant to melphalan, and the G3361/BCNU line, which was slightly (1.8-fold) resistant to melphalan. Collateral sensitivity of the G3361/CP, G3361/PAM, and G3361/4HC lines to killing by BCNU was also observed. Glutathione-S-transferase activity was elevated in each of the alkylating agent-resistant cell lines by 3- to 5-fold with chlorodinitrobenzene substrate. On Western blotting, the glutathione-S-transferase-pi (GST-pi) isoenzyme protein was elevated in the resistant cells by 3- to 5-fold. A complementary DNA (pTS4-10) coding for GST-pi has been cloned from a lambda gt11 library, sequenced, and used as a probe to determine the relative levels of GST-pi mRNA in the alkylating agent-resistant cell lines. GST-pi mRNA levels were elevated (8- to 15-fold) in the resistant cell lines, indicating that the GST-pi increases were mediated through an increase in mRNA levels. GST-pi elevations are a frequent event in cells selected for alkylating agent resistance, and in some cases, of multiple drug resistance. However, the lack of cross-resistance among cell lines selected for resistance to different alkylating agents, all of which have elevated GST-pi levels, indicates that increased levels of GST-pi cannot be the predominate mechanism for resistance to the tested drugs in these cell lines.

Alkylating Agents