PubMed Health⌕ Search

Biomedical subjects

C A Marotta

Publications and source records attributed to C A Marotta.

71 records · Page 4Linked to original sources
PubMed1977

Human beta-globin messenger RNA. I. Nucleotide sequences derived from complementary RNA.

Sequence analysis studies were carried out on human beta-globin mRNA (beta-mRNA) prepared from alpha-thalassemic, sickle cell, and Hb A reticulocytes. Highly purified beta-mRNA served as substrate for the preparation of cDNA by RNA-dependent DNA polymerase. The cDNA was transcribed by Escherichia coli RNA polymerase and the resulting cRNA was analyzed. Over 300 nucleotides were assigned to the beta-mRNA coding region and 37 nucleotides were assigned to the 3'-terminal noncoding region. The normal termination codon is UAA which is separated by 28 nucleotides from an out of phase UAA triplet. The origin of each of the abnormally long beta-globin variants Tak and Cranston is consistent with reduplication of dinucleotides prior to the normal termination codon, and both globin variants can terminate at the out of phase UAA.

Anemia, Sickle Cell↗
PubMed1977

Nucleotide sequence of 3' untranslated portion of human alpha globin mRNA.

We have determined the nucleotide sequence of 75 nucleotides of the 3'-untranslated portion of normal human alpha globin mRNA which corresponds to the elongated amino acid sequence of the chain termination mutant Hb Constant Spring. This was accomplished by sequence analysis of cDNA fragments obtained by restriction endonuclease or T4 endonuclease IV cleavage of human globin cDNA synthesized from globin mRNA by use of viral reverse transcriptase. Analysis of cRNA synthesized from cDNA by use of RNA polymerase provided additional confirmatory sequence information. Possible polymorphism has been identified at one site of the sequence. Our sequence overlaps with, and extends the sequence of 43 nucleotides determined by Proudfood and coworkers for the very 3'-terminal portion of human alpha globin mRNA. The complete 3'-untranslated sequence of human alpha globin mRNA (112 nucleotides including termination codon) shows little homology to that of the human or rabbit beta globin mRNAs except for the presence of the hexanucleotide sequence AAUAAA which is found in most eukaryotic mRNAs near the 3'-terminal poly (A).

Anemia, Sickle Cell↗
PubMed1977

Structure of human hemoglobin messenger RNA and its relation to hemoglobinopathies.

1. One-fifth to 1/4 of globin mRNA is untranslated sequence other than polyadenylic acid. 2. The untranslated sequences of mRNA vary markedly in their sequence and in their length. 3. Globin mRNAs demonstrate a marked bias in codon selection. 4. Viral mRNA shows a quite different pattern of codon selection; therefore, the selection of codons is not uniform for all mRNAs functioning in animal cells. 5. Elongated hemoglobin chains can be accounted for by frame-shift mutations, or point mutations within the normal termination codon. The additional amino acids are then coded for by sequences that are normally untranslated. 6. Certain hemoglobin deletion mutants occur at sites where there are partially reiterated sequences within the heomoglobin messenger RNA.

Base Sequence↗
PubMed1976

The primary structure of Bacillus subtilis and Bacillus stearothermophilus 5 S ribonucleic acids.

The nucleotide of Bacillus stearothermophilus 5 S RNA is pC-C-U-A-G-U-G-A-C-A-A-U-A-G-C-G-(G-A-G-A-G-G-)-A-A-A-C-A-C-C-C-G-U-U-C-C-C-A-U-C-C-C-G-A-A-C-A-C-G-G-A-A-G-U-U-A-A-G-C-U-C-U-C-C-A-G-C-G-C-C-G-A-U-G-G-U-A-G-U-U-G-G-G-G-C-C-A-G-C-G-C-C-C-C-U-G-C-A-A-G-A-G-U-A-G-G-U-C-G-U-U-G-C-U-A-G-G-COH; the nucelotide sequence of Bacillus subtilis 5 S RNA is pU-U-U-G-G-U-G-G-C-G-A-U-A-G-C-G-A-A-G-A-G-G-U-C-A-C-A-C-C-C-G-U-U-C-C-C-A-U-A-C-C-G-A-A-C-A-C-G-G-A-A-G-U-U-A-A-G-C-U-C-U-U-C-A-G-C-G-C-C-G-A-U-G-G-U-A-G-U-C-G-G-G-G-G-U-U-U-C-C-C-C-C-U-G-U-G-A-G-A-G-U-A-G-G-A-C-G-C-C-G-C-C-A-A-G-COH. Comparison of the sequence of B. stearothermophilus 5 S RNA to the sequence of B. subtilis 5 S RNA and to that of Bacillus megaterium 5 S RNA (Pribula, C. D., Fox, G. E., Woese, C. R., Sogin, M., and Pace, N. (1974) FEBS Lett. 44, 322-323) indicates that the 5 S RNA isolated from the thermophile contains unique nucleotide sequences not found in 5 S RNAs isolated from the two mesophilic species of genus Bacillus.

Bacillus subtilis↗
PubMed1976

Thermal denaturation of mesophilic and thermophilic 5S ribonucleic acids.

The Tm of Bacillus stearothermophilus 5S ribonucleic acid (RNA) is 1.5 +/- 0.5 C higher than that of 5S RNAs from B. subtilis and Escherichia coli. Melting in 50% methanol and in formaldehyde indicate that both base stacking and helical regions are involved in the slightly increased thermal stability of B. stearothermophilus 5S RNA. It is probable that the 5S RNA makes only a minor contribution to the thermostability of B. stearothermophilus 50S ribosomal subunits.

Bacillus subtilis↗
PubMed1975

Nucleotide sequences of the 3'-terminal untranslated region of messenger RNA for human beta globin chain.

In normal messenger RNA for the human beta-globin chain, nucleotide sequences have been identified which can be matched to the amino-acid sequence of the abnormally long segment of the beta-chain of hemoglobin Cranston. The finding of these sequences strengthens the hypothesis that the betaCranston chain arose by a frameshift mutation allowing the "readthrough" of the normal termination codon and translation of usually untranslated portions of the messenger RNA for the beta-globin chain. The oligonucleotides which match the amino-acid sequence of hemoglobin Cranston provide a sequence of 36 nucleotides which follows the normal beta-chain termination codon UAA.

Base Sequence↗
PubMed1974

Nucleotide sequences of human globin messenger RNA.

Globin messenger RNA, isolated from human peripheral blood reticulocytes, was transcribed into complementary DNA by use of the RNA-dependent DNA polymerase of avian myeloblastosis virus. The complementary DNA was then transcribed into (32)P-labeled complementary RNA by E. coli RNA polymerase in the presence of alpha-(32)P-labeled ribonucleoside triphosphates. The fingerprint pattern obtained from ribonuclease T1 digests of human globin complementary RNA was specific and reproducible. Different patterns were obtained from digests of duck, mouse, and rabbit globin complementary RNA. The fingerprint patterns obtained from digests of purified natural human 10S globin messenger RNA, labeled in vitro with (125)I or with [gamma-(32)P]ATP and polynucleotide kinase, were similar to that of the complementary RNA but contained some additional oligonucleotides. Sufficient nucleotide sequence information has been obtained from about 50% of the intermediate sized oligonucleotides (8-14 base residues long), to make possible examination of correspondence between these nucleotide sequences and globin amino-acid sequences. Approximately 70% of these oligonucleotide sequences can be matched to unique amino-acid sequences in the alpha- or beta-globin chains. The other 30% do not match known amino-acid sequences and presumably correspond to untranslated portions of the mRNA; some of these sequences, however, can be matched to amino-acid sequence in the abnormally long segment of the alpha chain of hemoglobin Constant Spring, which is thought to result from a chain-termination mutation.

Amino Acid Sequence↗
PubMedDate not supplied

Development of an anti-A beta monoclonal antibody for in vivo imaging of amyloid angiopathy in Alzheimer's disease.

We evaluated the efficacy of murine monoclonal antibodies (MAbs) targeted to the A beta amyloid of Alzheimer's disease for development of procedures for the in vivo identification of amyloid angiopathy (AA). MAbs to A beta were prepared and screened for effectiveness in visualizing AA and neuritic plaques in postmortem AD brain sections. They were assessed again after enzymatic cleavage to produce Fab fragments and after labeling with technetium-99m (99mTc) using a diamide dimercaptide ligand system. Modified and radiolabeled Fab fragments retained activity and specificity toward amyloid-laden blood vessels and neuritic plaques. A highly specific murine MAb, 10H3, was identified and characterized that fulfills criteria necessary for the development of an in vivo diagnostic imaging agent. Toxicity studies in rats showed the MAb to be safe. Biodistribution studies in mice demonstrated desirable properties for use as an imaging agent. Expansion and adaptation of these strategies may provide the methods and materials for the noninvasive analysis of AA in living patients, and permit assessment of the contribution of AA to the clinical and pathological features of AD.

Aged↗
PubMedDate not supplied

PC12 cells release stimulatory factors after transfection with beta/A4-C-terminal DNA of the Alzheimer amyloid precursor protein.

The beta/A4 region of the amyloid precursor protein (APP) accumulates in brains of victims of Alzheimer disease (AD) where it is a major component of senile plaques. We examined the pathophysiological consequences of overexpression of the beta/A4-C-terminal DNA in PC12 cells. Serum-free conditioned media (SFCM) from positive transfectants stimulated control PC12 cells to extend neurites and increase in size. Unlike the factor that affected cell size, neurite lengthening activity was significantly decreased after immunoabsorption with anti-beta/A4 monoclonal antibodies (MAb) and changes in pH. The data support the view that among the consequences of beta/A4-C-terminal DNA overexpression in PC12 cells is the release of factors that stimulate nontransfected cells to undergo morphological transformations that include differentiation to a neuronal phenotype. It is hypothesized that similar activities that may contribute to the molecular pathophysiology of the disorder may be present in the AD brain.

Adsorption↗
PubMedDate not supplied

Preparation of a recombinant cDNA library from poly(A+) RNA of the Alzheimer brain. Identification and characterization of a cDNA copy encoding a glial-specific protein.

Studies were undertaken to assess the extent to which messenger RNA prepared from the postmortem Alzheimer's disease (AD) brain can be used for the successful preparation of a recombinant cDNA library. Initial experiments focused on the glial-specific marker glial fibrillary acidic protein (GFAP) since GFAP expression appeared to be a model for further studies on mRNAs that may continue to be expressed at high levels in the vicinity of lesioned sites in the AD brain. An AD cDNA library, prepared in the lambda gt11 expression vector system contained GFAP-specific recombinants. One of these was sequenced and the insert was shown to exhibit 88% homology with the similar sequence from mouse GFAP. As established by Northern blots, the size of the GFAP mRNA prepared from the routinely acquired postmortem AD cortex, approximately 2.7 kb, was the same as from a neurologically normal control brain. These results agree with earlier studies on GFAP mRNA from fresh mouse brain. The results demonstrate that in the postmortem AD brain, astroglial-specific mRNA remains sufficiently stable for molecular genetic analysis and may serve as a useful model for examining the genetic expression of mRNAs that may be related to the molecular pathogenesis and the etiology of AD.

Aged↗
PubMedDate not supplied

Molecular and genetic investigations on Alzheimer brain amyloid.

Amyloid-containing plaques are a characteristic feature of the Alzheimer's disease brain and have been the object of study for decades. Only recently, however, have molecular and genetic techniques been applied to examination of amyloid in order to understand the factors that contribute to the accumulation of plaques in dementia. Current investigations have focused on the structure and properties of the amyloid protein, its corresponding messenger RNA, its cellular site of production, and its chromosomal site of origin. These data are discussed in the present review.

Aged↗
PubMedDate not supplied

Colocalization of amino terminal and A4 (beta-amyloid) antigens in Alzheimer plaques: evidence for coordinated processing of the amyloid precursor protein.

The mechanism by which the A4 (beta-amyloid) domain of the Alzheimer amyloid precursor protein (APP) is deposited in plaques is unknown, and limited information is available concerning the extent to which other APP sites are associated with plaques. To address these issues, we prepared antiserum to a peptide adjacent to the N-terminus of the APP (referred to as N1) and examined its distribution in brain relative to A4 by double-immunostaining techniques. Anti-N1 localized to both neurons and glia in control and Alzheimer patients. In the Alzheimer brain, anti-N1 detected plaques. Quantitation revealed that 85% of thioflavin-positive plaques, and 91% of A4-positive plaques were also N1 positive. Double-staining methods directly demonstrated colocalization of distant APP sites. The data suggest that suggest that proposed mechanisms for amyloid deposition during plaque formation must take into account the extracytoplasmic domain, in addition to the A4 region, rather than be confined exclusively to the A4 site.

Aged↗