An alternative splicing product of the lamin A/C gene lacks exon 10.
Expression of the A-type lamins was studied in the lung adenocarcinoma cell line GLC-A1. A-type lamins, consisting of lamin A and C, are two products arising from the same gene by alternative splicing. Northern blotting showed in GLC-A1 a relatively low expression level of lamin C and an even lower expression level of lamin A as compared to other adenocarcinoma cell lines. Immunofluorescence studies revealed highly irregular nuclear inclusions of lamin A, suggesting protein or gene expression abnormalities. Reverse transcriptase-polymerase chain reaction-based cDNA analysis followed by sequencing indicated the presence of an as yet unidentified alternative splicing product of the lamin A/C gene. This product differs from lamin A by the absence of the 5' part of exon 10 (90 nucleotides). Therefore we propose to designate this product lamin Adelta10. Deletion of the 30 amino acids encoded by exon 10 was predicted to result in a shift in pI of the protein from 7.4 to approximately 8.6, which was confirmed by two-dimensional immunoblotting. mRNA analysis in a variety of cell lines, normal colon tissue as well as carcinomas demonstrated the presence of lamin Adelta 10 in all samples examined, suggesting its presence in a variety of cell types.
Machiels
B M
BM
Department of Molecular Cell Biology and Genetics, University of Limburg, Maastricht, The Netherlands.
Zorenc
A H
AH
Endert
J M
JM
Kuijpers
H J
HJ
van Eys
G J
GJ
Ramaekers
F C
FC
Broers
J L
JL
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D017398:Alternative Splicing; D001483:Base Sequence; D002460:Cell Line; D003106:Colon / Q000378:metabolism; D017931:DNA Primers; D005091:Exons; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006801:Humans; D034904:Lamin Type A; D034882:Lamins; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D009838:Oligodeoxyribonucleotides; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D017384:Sequence Deletion; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D034904:Lamin Type A; D034882:Lamins; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; C440308:lamin C