==================================BSR53==================================
53. I want the sequence for exon 2 in the alpha-2 coding region of human
alpha globin.
1
UI - 87009038
AU - Shakin SH ; Liebhaber SA
TI - Translational profiles of alpha 1-, alpha 2-, and beta-globin messenger
ribonucleic acids in human reticulocytes.
AB - In human reticulocytes, the critical balancing of alpha- and beta-globin
synthesis may be controlled in part by differential translation of the
three major adult globin messenger RNAs (mRNAs), alpha 1, alpha 2, and
beta. In this study, we determined, as a parameter of translational
efficiency, the relative ribosome loading of these three mRNAs. Using
oligonucleotide probes specific for the alpha 1- and alpha 2-globin
mRNAs, we find that these two mRNAs have identical translational
profiles. Their distribution contrasts with that of beta-globin mRNA,
which is present on heavier polyribosomes and is less prevalent in
pre-80S messenger ribonucleoprotein fractions. The relative distribution
of alpha- vs. beta-globin mRNA is consistent with more efficient
beta-globin translation. In contrast, the parallel distributions of alpha
1- and alpha 2-globin mRNAs suggests they are translated with equal
efficiencies. Considering the relative concentrations of the two
alpha-globin mRNAs in normal reticulocytes, this result predicts a
dominant role for the alpha 2-globin locus in human alpha-globin
expression.
MH - Base Sequence ; Gene Expression Regulation ; Globin/*GENETICS ; Human ;
Polyribosomes/METABOLISM ; Reticulocytes/*METABOLISM ; RNA, Messenger/
*METABOLISM ; Support, U.S. Gov't, P.H.S. ; *Translation, Genetic
SO - J Clin Invest 1986 Oct;78(4):1125-9
2
UI - 87004552
AU - Jarman AP ; Nicholls RD ; Weatherall DJ ; Clegg JB ; Higgs DR
TI - Molecular characterisation of a hypervariable region downstream of the
human alpha-globin gene cluster.
AB - We have characterised an unusual, highly polymorphic region of DNA
located 8-kb downstream of the human alpha-globin gene complex. This
hypervariable region (alpha-globin 3' HVR) is composed of an array of
17-bp tandem repeats, the number of which differs considerably (70-450)
from one allele to another. The sequence of the 17-bp repeats is highly
conserved within and between alleles. Furthermore, this sequence
identifies a core oligonucleotide [5'-GNGGGG(N)ACAG-3'] that is common to
three previously characterised hypervariable regions. At reduced
stringency, a probe to the 3' HVR detects a new family of multiallelic
loci that will be of value in the study of human genetics.
MH - Alleles ; Base Sequence ; Cloning, Molecular ; DNA Restriction Enzymes ;
Evolution ; *Genes, Structural ; Globin/*GENETICS ; Human ; Nucleic Acid
Hybridization ; Repetitive Sequences, Nucleic Acid ; Support, Non-U.S.
Gov't ; *Variation (Genetics)
SO - EMBO J 1986 Aug;5(8):1857-63
3
UI - 86289452
AU - Scharf SJ ; Horn GT ; Erlich HA
TI - Direct cloning and sequence analysis of enzymatically amplified genomic
sequences.
AB - A method is described for directly cloning enzymatically amplified
segments of genomic DNA into an M13 vector for sequence analysis. A
110-base pair fragment of the human beta-globin gene and a 242-base pair
fragment of the human leukocyte antigen DQ alpha locus were amplified by
the polymerase chain reaction method, a procedure based on repeated
cycles of denaturation, primer annealing, and extension by DNA polymerase
I. Oligonucleotide primers with restriction endonuclease sites added to
their 5' ends were used to facilitate the cloning of the amplified DNA.
The analysis of cloned products allowed the quantitative evaluation of
the amplification method's specificity and fidelity. Given the low
frequency of sequence errors observed, this approach promises to be a
rapid method for obtaining reliable genomic sequences from nanogram
amounts of DNA.
MH - Antigens, Immune Response/*GENETICS ; Base Sequence ; Cloning, Molecular/
*METHODS ; Coliphages/*GENETICS ; DNA Polymerase I/METABOLISM ; Gene
Amplification ; *Genetic Vectors ; Globin/*GENETICS ; Human ; In Vitro ;
Polymorphism (Genetics)
SO - Science 1986 Sep 5;233(4768):1076-8
4
UI - 86205234
AU - Morle F ; Starck J ; Godet J
TI - Alpha-thalassemia due to the deletion of nucleotides -2 and -3 preceding
the AUG initiation codon affects translation efficiency both in vitro and
in vivo.
AB - We previously hypothesized that a 2 nucleotide deletion, causing a
A-greater than C change at position -3 preceding the ATG initiation codon
of alpha globin gene, reduced translation efficiency of alpha globin mRNA
and was responsible for a form of alpha + thalassemia displayed by an
Algerian patient. We presently show that this deletion leads to a 30-45%
reduction in translation efficiency of synthetic alpha globin mRNA in
rabbit reticulocyte lysate. In other experiments, we constructed alpha/G
gamma hybrid globin genes in which the 3' end of normal or mutated alpha
globin genes downstream to the ATG initiation codon was substituted by
the 3' part of a G gamma globin gene. COS cells transfected with either
of these 2 hybrid genes were shown to synthesize a similar amount of
alpha/G gamma hybrid mRNAs but 50% less G gamma globin when transfected
with the alpha/G gamma hybrid gene carrying the deletion. These results
definitively establish that the 2 nucleotide deletion reduces translation
efficiency by 30-50%. This contrasts with the 93% reduction induced by a
similar A-greater than C change at position -3 in the different
nucleotide context preceding the ATG codon of the rat preproinsulin gene.
MH - Base Sequence ; *Chromosome Deletion ; *Codon ; *Genes, Structural ;
Globin/*GENETICS/ISOLATION & PURIFICATION ; Human ; Macromolecular
Systems ; *Peptide Chain Initiation ; *RNA, Messenger ; Support, Non-U.S.
Gov't ; Templates ; Thalassemia/*FAMILIAL & GENETIC ; Transcription,
Genetic ; Translation, Genetic
SO - Nucleic Acids Res 1986 Apr 25;14(8):3279-92
5
UI - 86148516
AU - Hardison RC ; Sawada I ; Cheng JF ; Shen CK ; Schmid CW
TI - A previously undetected pseudogene in the human alpha globin gene
cluster.
AB - The sequence of the DNA between two pseudogenes in the human alpha-like
globin gene cluster has been determined. Comparison of this sequence with
sequences from other alpha-like globin gene clusters revealed another
pseudogene, psi alpha 2, between the previously recognized pseudogenes
zeta 1 and psi alpha 1. Therefore, the human alpha-like globin gene
family is organized 5'-zeta 2-zeta 1-psi alpha 2-psi alpha 1-alpha
2-alpha 1-3'. The new pseudogene psi alpha 2 is very close to zeta 1,
beginning only 65 base pairs 3' to the polyadenylation site of zeta 1.
The first exon and the first intron of psi alpha 2 are interrupted by
large inserts which are flanked by short (6 to 8 base pairs) direct
repeats. The pseudogene psi alpha 2 lacks a promoter for transcription by
RNA polymerase II, the first exon is highly divergent, one splice site is
mutated, and five different frameshift mutations have occurred in the
coding regions. Thus psi alpha 2 cannot encode a globin polypeptide. This
pseudogene was not recognized in previous hybridization analyses of the
human alpha-like globin gene cluster, and our discovery of it by sequence
analysis suggests that divergent copies of a large number of genes may
comprise a substantial fraction of the slowly renaturing DNA of mammalian
genomes.
MH - Base Sequence ; Comparative Study ; Genes ; Globin/*GENETICS ; Human ;
Linkage (Genetics) ; Nucleic Acid Hybridization ; Sequence Homology,
Nucleic Acid ; Support, U.S. Gov't, P.H.S.
SO - Nucleic Acids Res 1986 Feb 25;14(4):1903-11
NP (Y)