This domain is found in Saccharomyces cerevisiae protein SMP2, proteins with an N-terminal lipin domain and phosphatidylinositol transfer proteins. SMP2 is involved in plasmid maintenance and respiration. Lipin proteins are involved in adipose tissue development and insulin resistance.
This domain is found in lipins, lipin homologues from Saccharomyces cerevisiae (Smp2, PAH1) [ (PUBMED:16467296) ] and Schizosaccharomyces pombe (Ned1) [ (PUBMED:12376568) ], and in class II phosphatidylinositol transfer proteins (PITP) [ (PUBMED:23916246) ]. Lipin proteins are phosphatidate phosphatases which catalyse the dephosphorylation of phosphatidic acid to diacylglycerol, the penultimate step in triacylglycerol synthesis [ (PUBMED:23603613) ].
Family alignment:
There are 5196 LNS2 domains in 5194 proteins in SMART's nrdb database.
Click on the following links for more information.
Evolution (species in which this domain is found)
Taxonomic distribution of proteins containing LNS2 domain.
This tree includes only several representative species. The complete taxonomic breakdown of all proteins with LNS2 domain is also avaliable.
Click on the protein counts, or double click on taxonomic names to display all proteins containing LNS2 domain in the selected taxonomic class.
Literature (relevant references for this domain)
Primary literature is listed below; Automatically-derived, secondary literature is also avaliable.
Insulin-stimulated phosphorylation of lipin mediated by the mammalian target of rapamycin.
Proc Natl Acad Sci U S A. 2002; 99: 1047-52
Display abstract
The phosphorylation of a previously uncharacterized protein of apparent M(r) approximately 140,000 was found to be increased when rat adipocytes were incubated with insulin. The sequences of peptides generated by digesting the protein with trypsin matched perfectly with sequences in mouse lipin. Lipin is the product of the gene that is mutated in fatty liver dystrophy (fld) mice [Peterfy, M., Phan, J., Xu, P. & Reue, K (2001) Nat. Genet. 27, 121-124], which exhibit several phenotypic abnormalities including hyperlipidemia, defects in adipocyte differentiation, impaired glucose tolerance, and slow growth. When immunoblots were prepared with lipin antibodies, both endogenous adipocyte lipin and recombinant lipin overexpressed in HEK293 cells appeared as bands ranging in apparent M(r) from 120,000 to 140,000. Incubating adipocytes with insulin decreased the electrophoretic mobility and stimulated the phosphorylation of both Ser and Thr residues in lipin. The effects of insulin were abolished by inhibitors of phosphatidylinositol 3-OH kinase, and by rapamycin, a specific inhibitor of the mammalian target of rapamcyin (mTOR). The inhibition by rapamycin was blocked by FK506, which competitively inhibits those effects of rapamycin that are mediated by inhibition of mTOR. Moreover, amino acids, which activate mTOR, mimicked insulin by increasing lipin phosphorylation in a rapamycin-sensitive manner. Thus, lipin represents a target of the mTOR pathway, and potentially links this nutrient-sensing pathway to adipocyte development.
An evolutionarily conserved fission yeast protein, Ned1, implicated in normal nuclear morphology and chromosome stability, interacts with Dis3, Pim1/RCC1 and an essential nucleoporin.
J Cell Sci. 2002; 115: 4375-85
Display abstract
We identified a novel fission yeast gene, ned1(+), with pleiotropic mutations that have a high incidence of chromosome missegregation, aberrantly shaped nuclei, overdeveloped endoplasmic reticulum-like membranes, and increased sensitivity to a microtubule destabilizing agent. Ned1 protein, which was phosphorylated in a growth-related manner, interacted in a yeast two-hybrid system with Dis3 as well as with Pim1/RCC1 (nucleotide exchange factor for Ran). Ned1 also interacted with an essential nucleoporin, a probable homologue of mammalian Nup98/96. The ned1 gene displayed a variety of genetic interactions with factors involved in nuclear transport and chromosome segregation, including the crm1 (exportin), spi1 (small GTPase Ran), pim1, and dis genes. A substitution mutation that affected the two-hybrid interaction with Dis3 increased chromosome instability, suggesting the functional importance of the interaction. Overproduction of Ned1 protein induced formation of an abnormal microtubule bundle within the nucleus, apparently independently of the spindle pole body, but dependent on pim1(+) activity. The ned1(+) gene belongs to an evolutionarily conserved gene family, which includes the mouse Lpin genes, one of whose mutations is responsible for lipodystrophy.
A gene, SMP2, involved in plasmid maintenance and respiration in Saccharomyces cerevisiae encodes a highly charged protein.
Mol Gen Genet. 1993; 236: 283-8
Display abstract
The smp2 mutant of Saccharomyces cerevisiae shows increased stability of the heterologous plasmid pSR1 and YRp plasmids. A DNA fragment bearing the SMP2 gene was cloned by its ability to complement the slow growth of the smp2 smp3 double mutant (smp3 is another mutation conferring increased stability of plasmid pSR1). The nucleotide sequence of SMP2 indicated that it encodes a highly charged 95 kDa protein. Disruption of the genomic SMP2 gene resulted in a respiration-deficient phenotype, although the cells retained mitochondrial DNA, and showed increased stability of pSR1 like the original smp2 mutant. The fact that the smp2 mutant is not always respiration deficient and shows increased pSR1 stability even in a rho0 strain lacking mitochondrial DNA suggested that the function of the Smp2 protein in plasmid maintenance is independent of respiration. The SMP2 locus was mapped at a site 71 cM from lys7 and 21 cM from ilv2/SMR1 on the right arm of chromosome XIII.
Links (links to other resources describing this domain)
