Exon-intron organization and chromosomal localization of the mouse monoglyceride lipase gene

Monoglyceride lipase (MGL) functions together with hormone-sensitive lipase to hydrolyze intracellular triglyceride stores of adipocytes and other cells to fatty acids and glycerol. In addition, MGL presumably complements lipoprotein lipase in completing the hydrolysis of monoglycerides resulting from degradation of lipoprotein triglycerides. Cosmid clones containing the mouse MGL gene were isolated from a genomic library using the coding region of the mouse MGL cDNA as probe. Characterization of the clones obtained revealed that the mouse gene contains the coding sequence for MGL on seven exons, including a large terminal exon of approximately 2.6 kb containing the stop codon and the complete 3' untranslated region. Two different 5' leader sequences, diverging 21 bp upstream of the predicted translation initiation codon, were isolated from a mouse adipocyte cDNA library. Western blot analysis of different mouse tissues revealed protein size heterogeneities. The amino acid sequence derived from human MGL cDNA clones showed 84% identity with mouse MGL. The mouse MGL gene was mapped to chromosome 6 in a region with known homology to human chromosome 3q21.     

Carrier DNA affects the integration of HSV-1 TK gene in the genome of L929TK- cells.

L929TK- cells were cotransfected with DNA mixtures containing tk gene of HSV-1, plasmids carrying LTR of MoMLV or RSV and carrier DNA of salmon sperm or chromosomal DNA of recipient cells. Selection of TK+ transformants was conducted in DMEM supplemented with HAT. Plasmids carrying LTR sequences of MoMLV or RSV retroviruses showed enhancing effect on the frequency of TK+ transformation. Southern blot analysis of chromosomal DNA of TK+ transformants demonstrated in clones deriving from cotransfections of tk gene and carrier DNA of L929TK- cells multiple copies of tk gene integrated into several genomic sites of host. Single copies of tk gene integrated into different sites of host genome occurred in chromosomal DNA of TK+ clones deriving from cotransfections of tk gene and carrier DNA of salmon sperm. Cells cotransfected with tk gene and plasmids carrying LTR sequences of MoMLV or RSV formed three dimensional colonies in semisolid agar medium. No effect of carrier DNA on the morphology of TK+ transformant clones was noticed.     

Carp growth hormone: molecular cloning and sequencing of cDNA

cDNA clones of the fish Cyprinus carpio growth hormone (GH) mRNA have been isolated from a cDNA library prepared from carp pituitary gland poly(A)+RNA. The nucleotide sequence of one of the carp GH cDNA clones containing an insert of 1164 nucleotides (nt) was determined. The cDNA sequence was found to encode a polypeptide of 210 amino acids (aa) including a signal peptide of 22 aa and to contain 5' and 3' untranslated regions of the mRNA of 36 and 498 nt, respectively. The carp GH presents a 63% amino acid sequence homology with the salmon GH, has structural features common with other GH polypeptides of mammalian or avian origin and contains domains of conserved sequence near the N- and C-terminal regions. Southern blot hybridization of carp genomic DNA with GH cDNA probes shows the presence of at least two GH-coding sequences in the fish genome.     

Isolation and complete nucleotide sequence of the gene for bovine parathyroid hormone

The structure of the bovine parathyroid hormone (PTH) gene has been analyzed by Southern blot hybridization of genomic DNA and by nucleotide sequence analysis of a cloned PTH gene. In the Southern analysis, several restriction enzymes produced single fragments that hybridized to PTH cDNA suggesting that there is a single bovine PTH gene. The restriction map of the cloned gene is the same as that determined by Southern blot analysis of bovine DNA. The sequence of 3154 bp of the cloned gene has been determined including 510 bp and 139 bp in the 5' and 3' flanking regions, respectively. The gene contains two introns which separate three exons that code primarily for: (i) the 5' untranslated region, (ii) the pre-sequence of preProPTH, and (iii) PTH and the 3' untranslated region. The gene contains 68% A + T and unusually long stretches of 100- to 150-bp sequences containing alternating A and T nucleotides in the 5' flanking region and intron A. The 5' flanking region contains two TATA sequences, both of which appear to be functional as determined by S1 nuclease mapping. Compared to the rat and human genes, the locations of the introns are identical but the sizes differ. Comparable human and bovine sequences in the flanking regions and introns are about 80% homologous.     

Human profilin. Molecular cloning, sequence comparison, and chromosomal analysis

Profilin is an ubiquitous 12-15-kDa actin monomer-binding protein, the amino acid sequence of which was previously reported for the cow and Acanthamoeba. In the latter species, two isoforms of profilin have been identified. We have isolated full-length profilin cDNA clones from a human HepG2 library. All clones have the same nucleotide sequence, and Northern blot and RNase protection analyses of human tissues indicate that all tissues have the same approximately 850 base message, and provide no evidence of alternative message splicing. This result strongly implies a single profilin isoform in human cells, although differential post-translational modifications have not been excluded. Northern blot analysis extends the tissue distribution of profilin to include epithelial, muscle, and renal tissues. Comparison of the predicted human profilin amino acid sequence with that of published bovine profilin indicates 90% identity with a single 3-residue deletion in the human sequence. Southern blot analysis of somatic cell hybrid DNA indicates at least four dispersed genetic loci in the human genome hybridize with the profilin cDNA as well as untranslated region fragments, suggesting several of these loci represent pseudogenes of recent evolutionary origin. In addition, 5' and 3' untranslated regions are conserved between humans and rodents, implying a functional role for these regions of the profilin gene.     

Molecular cloning and sequence analysis of cDNAs encoding porcine kidney D-amino acid oxidase

Complementary DNAs encoding D-amino acid oxidase (EC 1.4.3.3, DAO), one of the principal and characteristic enzymes of the peroxisomes of porcine kidney, have been isolated from the porcine kidney cDNA library by hybridization with synthetic oligonucleotide probes corresponding to the partial amino acid sequences. Analysis of the nucleotide sequences of two clones revealed a complete 3211-nucleotide sequence with a 5'-terminal untranslated region of 198 nucleotides, 1041 nucleotides of an open reading frame that encoded 347 amino acids, and a 3'-terminal untranslated region of 1972 nucleotides. The deduced amino acid sequence was completely identical with the reported sequence of the mature enzyme [Ronchi, S., Minchiotti, L., Galliano, M., Curti, B., Swenson, R. P., Williams, C. H. J., & Massey, V. (1982) J. Biol. Chem. 257, 8824-8834]. These results indicate that the primary translation product does not contain a signal peptide at its amino-terminal region for its translocation into peroxisomes. RNA blot hybridization analysis suggests that porcine kidney D-amino acid oxidase is encoded by three mRNAs that differ in size: 3.3, 2.7, and 1.5 kilobases. Comparison of the sequences of the two cDNA clones revealed that multiple polyadenylation signal sequences (ATTAAA and AACAAA) are present in the 3'-untranslated region, making the different mRNA species. The efficiency of 3' processing of the RNA was quite different between the two signal sequences ATTAAA and AACAAA. Southern blot analysis showed the presence of a unique gene for D-amino acid oxidase in the porcine genome.     

Molecular cloning and nucleotide sequence of the cDNA for sperm-specific lactate dehydrogenase-C from mouse.

Mouse sperm-specific lactate dehydrogenase-C (LDH-C) cDNA was cloned and sequenced from lambda gt11 expression library. The LDH-C cDNA insert of 1236 bp consists of the protein-coding sequence (999 bp), the 5' (54 bp) and 3' (113 bp) non-coding regions, and the poly(A) tail (70 bp). The Northern blot analysis of poly(A)-containing RNAs from mouse testes and liver indicates that the LDH-C gene is expressed in testes but not in liver, and that its mRNA is approx. 1400 nucleotides in length. The nucleotide and amino acid sequences of the mouse LDH-C cDNA show 73% and 72% homologies, respectively, with those of the mouse LDH-A. The Southern blot analysis of genomic DNAs from mouse liver and human placenta indicates the presence of multiple LDH-C gene-related sequences.     

Molecular cloning, cDNA structure, and regulation of the regulatory subunit of type II cAMP-dependent protein kinase from rat ovarian granulosa cells

One isoform of the regulatory subunit of type II cAMP-dependent protein kinase (R-II51; Mr = 51,000) and its electrophoretic variants (R-II51.5 and R-II52; Mr = 51,500 and 52,000, respectively) are selectively induced by estradiol and follicle-stimulating hormone (cAMP) in rat ovarian granulosa cells. To ascertain the amino acid sequence of R-II51 and to gain insight into the molecular events regulating the intracellular content of ovarian follicular R-II51, we constructed a lambda gt11 cDNA expression library from poly(A)+ RNA of hormone-primed rat granulosa cells. A 1.5-kilobase (kb) cDNA insert, isolated from a plaque-purified R-II antibody positive bacteriophage clone, selectively bound R-II51 mRNA as demonstrated by analysis of the hybrid-selected translation product. Restriction maps and sequence analyses of the 1.5-kb cDNA insert and of the 1.8- and 2.2-kb cDNA inserts from two additional clones showed overlapping sequences which span a region of 3065 nucleotides in size. The 1.5- and 1.8-kb cDNA inserts each contained poly(A) addition signals (1508 and 1761 nucleotides, respectively), terminal poly(A) sequences, and the entire coding region for R-II51 (1204 nucleotides) except for a small number of nucleotides at the 5' end. The 2.2-kb cDNA insert contained 394 nucleotides of the coding region a long 3' untranslated region and two more poly(A) addition signals (3041 and 3059 nucleotides). An amino acid microsequence surrounding the autophosphorylation site of pure rat ovarian R-II51 agreed with the amino acid sequence deduced from the nucleotide sequence of the cDNA. Northern blot analyses demonstrated two major mRNA species (1.8 and 3.2 kb in size) in hormone-primed rat ovaries which were approximately 10- and 50-fold greater than the R-II mRNA content in rat brain and rat heart, respectively. Southern blot analysis of rat liver DNA indicated that a single gene codes for R-II51 mRNA. Structural differences among rat ovarian R-II51, rat heart R-II54, and the known amino acid sequences of bovine R-II and R-I subunits also indicate that the rat ovarian R-II51 subunit is the product of a distinct gene.     

Preparation of a "functional library" of African green monkey DNA fragments which substitute for the processing/polyadenylation signal in the herpes simplex virus type 1 thymidine kinase gene.

Fragments of African green monkey (Cercopithecus aethiops) DNA (3.5 to 18.0 kilobases) were inserted downstream from the thymidine kinase (TK, tk) coding region in pTK206/SV010, a gene construct which lacks both copies of the hexanucleotide 5'-AATAAA-3' and contains a simian virus 40 origin of replication, allowing it to replicate in Cos-1 cells. No polyadenylated tk mRNA was detected in Cos-1 cells transfected by pTK206/SV010. The ability of simian DNA fragments to restore tk gene expression was examined by measuring the incorporation of [125I]iododeoxycytidine into DNA in Cos-1 cells transfected by pTK206/SV010 insertion derivatives. tk gene expression was restored by the insertion in 56 of the 67 plasmids analyzed, and the level of expression equaled or exceeded that obtained with the wild-type tk gene in 30 of these. In all plasmids examined that showed restoration of tk gene expression, polyadenylated tk mRNA of discrete size was detected. The sizes of these tk mRNAs were consistent with the existence of processing and polyadenylation signals within the inserted DNA fragments. The frequency with which inserted fragments restored tk gene expression suggests that the minimal signal for processing and polyadenylation is a hexanucleotide (AAUAAA or a similar sequence). LTK- cells were biochemically transformed to TK+ with representative insertion constructs. pTK206/SV010 transformed LTK- cells at a very low frequency; the frequency of transformation with insertion derivatives was 40 to 12,000 times higher.     

Human gastric intrinsic factor: characterization of cDNA and genomic clones and localization to human chromosome 11

A human gastric intrinsic factor (IF) cDNA clone was isolated using a rat cDNA clone as a probe. Comparison of the predicted amino acid sequence revealed 80% identity of human IF with rat IF. These cDNA clones were used to isolate and map two overlapping clones encoding the human IF gene. The first exon of the cloned region (exon 2) contains 30 bp of the 5' untranslated region, the signal peptide, and the first 8 amino acids of the mature protein. Exons 3-10 encode the remainder of the coding and 3' noncoding regions. Southern analysis of genomic DNA indicated the presence of a single human IF gene and also revealed the presence of strong hybridizing sequences in genomic DNA from monkey, rat, mouse, cow, and human, suggesting that the IF gene is well conserved. The IF gene was localized to human chromosome 11 by concurrent cytogenetic and cDNA probe analysis of a panel of human X mouse somatic cell hybrids. Southern analysis of genomic DNA from patients with congenital pernicious anemia (lacking intrinsic factor) revealed normal restriction fragment patterns, suggesting that a sizable gene deletion was not responsible for the deficiency.     

Characterization and nucleotide sequence of the gene for the common alpha subunit of the bovine pituitary glycoprotein hormones.

The gene coding for the common alpha subunit of the bovine pituitary glycoprotein hormones was isolated from a bovine genomic library. The gene spans roughly 16.5 kbp, contains three intervening sequences, and codes for a message of approximately 730 nucleotides. The complete coding region of the gene was sequenced as well as 315 nucleotides of 5' flanking sequence and the entire intron C. Only a single base difference was found when the sequence of the gene was compared with that of the cDNA. Genomic blotting experiments suggest the presence of a single alpha subunit gene. Comparison of the bovine and human alpha subunit genes indicated that the high level of homology observed in the coding regions has been maintained throughout the 5' and 3' untranslated regions, and at least 90 nucleotides of the 5'flanking regions. Additionally, there is an 18 base pair sequence present in both the 5' flanking and 5' untranslated regions of the gene that is homologous to a region of the chick ovalbumin gene. This ovalbumin sequence has been suggested as a binding site for the progesterone receptor-complex.