lamin Dm0, Dm0, Dm0, lamin Dm0, lamin B
an intermediate filament protein - chromatin associated protein - Lamin binds to scaffold/matrix-associated regions, DNA sequences that are held responsiblefor mediating the interaction between the nuclear matrix and chromatin.
Gene model reviewed during 5.55
Annotated transcripts do not represent all supported alternative splices within 5' UTR.
Gene model reviewed during 5.45
Low-frequency RNA-Seq exon junction(s) not annotated.
Gene model reviewed during 5.56
3.0, 2.8 (northern blot)
622 (aa); 76 (kD observed); 71 (kD predicted)
Three forms of lamin have been identified in D.melanogaster, lamin Dm0 is rapidly processed to lamin Dm1 in the cytoplasm, Dm1 is then assembled in the nuclear envelope and is then phosphorylated, forming lamin Dm2.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Lam using the Feature Mapper tool.
The 3.0 kb Lam transcript is expressed at all stages, from embryo to adult. Although the 2.8 kb Lam transcript predominates in late oogenesis and early embryogenesis, the 3.0 kb transcript predominates starting at 2-3 hours of embryogenesis. Both transcripts encode the same polypeptide, and differ in their 3'-untranslated regions.
Lam protein is a nuclear envelope polypeptide which remains in an envelope-like structure enclosing the mitotic apparatus throughout mitosis.
Full-length Lam is abundant at 8 hours APF, but decreases from 10-12 hours APF, and is at low to absent levels at 14 hours APF. Cleaved Lam is observed starting at 10 hours APF, and is abundant by 14 hours APF.
Lam protein is a component of the individualization complex in late spermatogenesis.
Between stages S4 and S6-S7 of oogenesis, Lam protein localizes to the nuclear periphery in all cell types, but after stage S6-S7, nucleoplasmic and cytoplasmic accumulation is also observed. During larval, pupal and adult stages Lam protein localizes to the nucleus of most cells. No Lam protein is detected during stages 6-11 of spermiogenesis.
GBrowse - Visual display of RNA-Seq signalsView Dmel\Lam in GBrowse 2
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Source for identity of: Lam CG6944
Lam is required in the cyst stem cell lineage but is dispensible in both the germline and the hub cells in the testis.
Lam is required to regulate organisation of the stem cell niche in the testis so that both the cyst stem cells and germline stem cells can assume proper interactions with the hub.
DNA-protein interactions: genome-wide binding profile assayed for Lam protein in Kc167 cells; see Chromatin_types_NKI collection report. Individual protein-binding experiments listed under "Samples" at GEO_GSE22069 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE22069).
RNAi generated by PCR using primers directed to this gene causes a cell growth and viability phenotype when assayed in Kc167 and S2R+ cells.
Mutations in Lam disrupt the directed outgrowth of the cytoplasmic extensions from terminal cells of the tracheal system. Female germline mutant clones disrupt the dorsal-ventral polarity of the oocyte.
Identification: Enhancer trap expression pattern survey for loci expressed in the ring gland.
Biochemical techniques reveal that in living cells lamins are closely associated with both DNA and RNA.
The Lam gene product is essential for the structural integrity of the nuclear envelope and for the correct integration of nuclear pore complexes into the nuclear membrane.
Region of a DNA fragment, λ20p1.4, which is a moderately repetitive sequence of the genome present in about 120 copies per haploid genome, polymerises with purified Lam.
The alpha-helical rod domain of Lam is sufficient for the specific interaction with the M/SAR fragment of ftz. For this specific interaction to occur it is essential that Lam is organised above the level of the dimer.
Identified as being specifically expressed in the terminal cells of the developing tracheal system and required for the formation and outgrowth of the terminal branches.
Monoclonal antibody ADL84 is specific for Lam Dm1 and does not bind Lam Dm2. The antibody demonstrates that isolated interphase Lams Dm1 and Dm2 occur as mixed dimers, indicating random interactions. Mapping of the epitope for ADL84 shows Lam Dm2-specific phosphorylation takes place in the amino terminal head domain, most likely at Ser25.
Nuclear assembly has been followed in a cell free system: the Lam gene product plays essential role in nuclear envelope assembly.
Three isoforms of Lam protein have been purified and their activity in vitro has been studied.
Some Lam protein is apparently retained in an envelope-like structure throughout mitosis in early Drosophila embryos.
A soluble isoform of Lam protein has been identified in the extracts of cultured cells blocked in mitosis. This isoform is the only species detectable in late-stage egg chambers and early embryos. The conversion of nuclear isoforms of Lam protein to this soluble isoform is mediated by a specific rearrangement of phosphate groups rather than large net changes in the levels of Lam protein phosphorylation. The residues involved in the phosphorylation/dephosphorylation reactions have been tentatively mapped within the fragment containing amino acids 385-547.
l(2)25Ec was included as part of a study of the 24D4--25F2 region.
Gene identified by screening a lambda-gt11 cDNA expression library, constructed from early embryonic mRNA, with monoclonal antibodies against Drosophila lamin. The structural gene for nuclear lamin. Translated as a prolamin of apparent molecular mass of 76kD, which is quickly processed to a 74kD species, presumably by proteolysis. The processed polypeptide is assembled into the nuclear envelope, where it becomes phosphorylated and again attains a mass of 76kD (Smith, Gruenbaum, Berrios, and Fisher, 1987).
The gene is named "misguided" because terminal branches of the tracheal system do not follow the normal patterns of projection during branch outgrowth in mutants.