The gene for a novel human lamin maps at a highly transcribed locus of chromosome 19 which replicates at the onset of S-phase.
A previously described human DNA fragment which is replicated early in S-phase of HL-60 cell DNA (C. Tribioli, G. Biamonti, M. Giacca, M. Colonna, S. Riva, and A. Falaschi, Nucleic Acids Res. 15:10211-10232, 1987) was used to screen a genomic library in lambda Ch28. A clone which contained a 13.7-kb insert (L30E) found to code for several transcripts was isolated. The transcription of L30E DNA exhibited a complex pattern and a tissue-specific and proliferation-dependent type of regulation. The data were consistent with two tandemly arranged transcription units, the 3' end of one separated from the 5' end of the other by a sequence of about 600 bp containing an active promoter. The isolation and sequencing of L30E-specific cDNAs permitted identification of two genes, one of which encoded a B-type human lamin (analogous to mouse lamin B2). L30E DNA was mapped by in situ hybridization at the G-negative subtelomeric band p13.3 of chromosome 19. Interestingly, in synchronized HL-60 cells, L30E DNA is replicated in the first minute of S-phase. Replication of the lamin gene early in S-phase may reflect a coupling between early replication and transcription of genes for S-phase-specific proteins such as lamins.
Biamonti
G
G
Istituto di Genetica Biochimica ed Evoluzionistica del Consiglio Nazionale delle Ricerche, Pavia, Italy.
Giacca
M
M
Perini
G
G
Contreas
G
G
Zentilin
L
L
Weighardt
F
F
Guerra
M
M
Della Valle
G
G
Saccone
S
S
Riva
S
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002478:Cells, Cultured; D002874:Chromosome Mapping; D002888:Chromosomes, Human, Pair 19; D003001:Cloning, Molecular; D015342:DNA Probes; D004261:DNA Replication; D005091:Exons; D005260:Female; D015698:Genomic Library; D005914:Globins / Q000235:genetics; D006801:Humans; D034921:Lamin Type B; D034882:Lamins; D015473:Leukemia, Promyelocytic, Acute; D008214:Lymphocytes / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D010920:Placenta / Q000502:physiology; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D015183:Restriction Mapping; D016196:S Phase / Q000502:physiology*; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D015342:DNA Probes; D034921:Lamin Type B; D034882:Lamins; D009687:Nuclear Proteins; D005914:Globins