Genomic Structure and Chromosomal Localization of Mouse Cyclin G1 Gene

Mouse genomic DNA harboring the full coding sequence of cyclin G1 was cloned and analyzed. The locations of five coding exons and the intron–exon boundary sequences were found to be conserved between the mouse and the human genes. Two putative binding sites for thep53tumor suppressor gene product were found around the first exon: one was located in the 5′ regulatory region, and the other was in the first intron. The mouse cyclin G1 gene was mapped to bands A5 to B1 of chromosomes 11 (11A5–B1) by FISH using genomic DNA clone as a biotinylated probe. The location of mouse cyclin G1 is syntenic to that of its human homologue, which we previously mapped to 5q32–q34 of chromosome 5. An additional faint signal was detected on chromosome 4 (4B1–C2), probably indicating the presence of a cyclin G1-related gene or pseudogene in the mouse genome.     

Mouse and Human Neuronal Pentraxin 1 (NPTX1): Conservation, Genomic Structure, and Chromosomal Localization

We have previously identified novel members of the pentraxin family (neuronal pentraxin 1 and 2) that are expressed in the nervous system. Neuronal pentraxin 1 (NP1) was identified as a rat protein that may mediate the uptake of synaptic material and the presynaptic snake venom toxin, taipoxin. NP2 was identified as a separate gene discovered by screening for a human homolog for NP1. Here, we report human cDNA and mouse genomic DNA sequences for NP1 (gene symbol NPTX1). Human NP1 and mouse NP1 show 95 and 99% amino acid identity, respectively, with rat NP1 and conserve all potential glycosylation sites. Like rat NP1, human NP1 message is large (6.5 kb) and is exclusively localized to the nervous system. The mouse NP1 gene is 13 kb in length and contains four introns that break the coding sequence of NP1 in the same positions as the introns of the human NP2 gene. The human and mouse NP1 genes are localized to chromosome 17q25.1–q25.2 and chromosome 11e2–e1.3, respectively. These data demonstrate the existence of a separate family of pentraxin proteins that are expressed in the human brain and other tissues and that may play important roles in the uptake of extracellular material.     

人同源框基因Lhx4 cDNA序列的获得,染色体定位和基因组分析

Lhx4基因是LIM同源框基因家族的一员 ,它在运动神经元的发育过程中发挥着重要的作用 .从人脊髓cDNA文库中筛选到了 1个人源性Lhx4基因的cDNA全长序列 ,它与鼠源性的Lhx4基因的cDNA序列有 92 %同源性 .它的基因被定位在 1号染色体 1q 2 4 .1- 1q 2 4 .3的位置 ,并包含有 6个外显子 .其中同源框结构域由外显子 4和 5表达 ,LIM结构域 1由外显子 2表达 ,LIM结构域2由外显子 3表达 .     

Chromosomal Localization of the Human Genes for α1A, α1B, and α1E Voltage-Dependent Ca Channel Subunits

The α₁ subunit genes encoding voltage-dependent Ca²⁺ channels are members of a gene family. We have used human brain cDNA probes to localize the neuronal isoform genes CACNL1A4 (α_1A), CACNL1A5 (α_1B), and CACNL1A6 (α_1E) to 19p13, 9q34, and 1q25-q31, respectively, using fluorescence in situ hybridization on human chromosomes. These genes are particularly interesting gene candidates in the pathogenesis of neuronal disorders. Although genetic disorders have been linked to loci 9q34 and 19p13, no genetic disease related to Ca²⁺ signaling defects has yet been linked to these loci.     

Chromosomal localization of the human interleukin 1α (IL-1α) gene

The human interleukin 1α gene was assigned to chromosome 2 using Southern transfer analysis of human-rodent somatic cell hybrid DNAs. The gene was regionally localized to 2q12–21 using in situ hybridization to metaphase chromosomes. These results indicate that the IL-1α gene maps to the same general region on the long arm of chromosome 2 as the IL-1β gene, which has been previously assigned.     

The Laminin α Chains: Expression, Developmental Transitions, and Chromosomal Locations of α1-5, Identification of Heterotrimeric Laminins 8–11, and Cloning of a Novel α3 Isoform

Laminin trimers composed of α, β, and γ chains are major components of basal laminae (BLs) throughout the body. To date, three α chains (α1–3) have been shown to assemble into at least seven heterotrimers (called laminins 1–7). Genes encoding two additional α chains (α4 and α5) have been cloned, but little is known about their expression, and their protein products have not been identified. Here we generated antisera to recombinant α4 and α5 and used them to identify authentic proteins in tissue extracts. Immunoprecipitation and immunoblotting showed that α4 and α5 assemble into four novel laminin heterotrimers (laminins 8–11: α4β1γ1, α4β2γ1, α5β1γ1, and α5β2γ1, respectively). Using a panel of nucleotide and antibody probes, we surveyed the expression of α1-5 in murine tissues. All five chains were expressed in both embryos and adults, but each was distributed in a distinct pattern at both RNA and protein levels. Overall, α4 and α5 exhibited the broadest patterns of expression, while expression of α1 was the most restricted. Immunohistochemical analysis of kidney, lung, and heart showed that the α chains were confined to extracellular matrix and, with few exceptions, to BLs. All developing and adult BLs examined contained at least one α chain, all α chains were present in multiple BLs, and some BLs contained two or three α chains. Detailed analysis of developing kidney revealed that some individual BLs, including those of the tubule and glomerulus, changed in laminin chain composition as they matured, expressing up to three different α chains and two different β chains in an elaborate and dynamic progression. Interspecific backcross mapping of the five α chain genes revealed that they are distributed on four mouse chromosomes. Finally, we identified a novel full-length α3 isoform encoded by the Lama3 gene, which was previously believed to encode only truncated chains. Together, these results reveal remarkable diversity in BL composition and complexity in BL development.     

Cloning, Chromosomal Localization, and Physical Linkage of the β and γ Subunits (SCNN1B and SCNN1G) of the Human Epithelial Amiloride-Sensitive Sodium Channel

Three subunits of the amiloride-sensitive Na⁺ channel, named α, β, and γ, have previously been cloned in rat colon. The human lung α chain (SCNN1A) has also been cloned and its gene localized on chromosome 12p13. We now report the molecular cloning of the human lung β (SCNN1B) and γ (SCNN1G) chains. In situ hybridization and pulsed-field electrophoresis experiments demonstrate that both genes are located within a common 400-kb fragment on chromosome 16p12-p13. Screening of the cDNA library reveals two forms of the β subunit that differ by the presence or absence of a 464-bp fragment in the 3′ region. A frameshift in the short form modifies the COOH terminal sequence of the corresponding protein. Since several similar frameshifts mutations have recently been reported in patients affected by a rare form of hypertension, the existence of COOH truncated forms of the β chain might be of physiological importance.     

Expression and regulation of α1β1 integrin in Schwann cells

The interaction of cells with the extracellular matrix plays a critical role in morphogenesis and cell differentiation. To define how Schwann cells might interact with the extracellular matrix, we chose to study the expression of the laminin/collagen receptor α1β1 integrin during nerve development in the rat from embryonic day 14 to maturity. We found that this integrin is expressed predominantly on mature non-myelin-forming cells and only at very low levels on myelin-forming cells. Significant levels of this integrin were not detected on Schwann cell precursors or embryonic Schwann cells in vivo. Experiments using transected and crushed sciatic nerve showed that α1β1 integrin expression is regulated at least in part by axonal contact. Furthermore, Schwann cell culture experiments showed that α1β1 integrin levels are strongly upregulated by transforming growth factor-βs and phorbol esters. © 1997 John Wiley & Sons, Inc. J Neurobiol 33: 914–928, 1997     

Osteopontin mediates macrophage chemotaxis via α4 and α9 integrins and survival via the α4 integrin

Osteopontin (OPN) is highly expressed by macrophages and plays a key role in the pathology of several chronic inflammatory diseases including atherosclerosis and the foreign body reaction. However, the molecular mechanism behind OPN regulation of macrophage functions is not well understood. OPN is a secreted molecule and interacts with several integrins via two domains: the RGD sequence binding to α_v‐containing integrins, and the SLAYGLR sequence binding to α₄β₁, α₄β₇, and α₉β₁ integrins. Here we determined the role of OPN in macrophage survival, chemotaxis, and activation state. For survival studies, OPN treated‐bone marrow derived macrophages (BMDMs) were challenged with growth factor withdrawal and neutralizing integrin antibodies. We found that survival in BMDMs is mediated primarily through the α₄ integrin. In chemotaxis studies, we observed that migration to OPN was blocked by neutralizing α₄ and α₉ integrin antibodies. Further, OPN did not affect macrophage activation as measured by IL‐12 production. Finally, the relative contributions of the RGD and the SLAYGLR functional domains of OPN to leukocyte recruitment were evaluated in an in vivo model. We generated chimeric mice expressing mutated forms of OPN in myeloid‐derived leukocytes, and found that the SLAYGLR functional domain of OPN, but not the RGD, mediates macrophage accumulation in response to thioglycollate‐elicited peritonitis. Collectively, these data indicate that α₄ and α₉ integrins interacting with OPN via the SLAYGLR domain play a key role in macrophage biology by regulating migration, survival, and accumulation. J. Cell. Biochem. 114: 1194–1202, 2013. © 2012 Wiley Periodicals, Inc.     

Inhibition of adipose differentiation by 9α, 11β-prostaglandin F2α

Prostaglandin F2α (PGF2α) is a potent adipose differentiation inhibitor for the adipogenic cell line 1246 and for adipocyte precursors in primary culture with an ED50 of 3×10⁻⁸ M. In this paper, we examined the effect of several prostaglandins which have structural similarities with PGF2α on the differentiation of 1246 cells and of adipocyte precursors in primary culture. The results show that only 9α,11β-PGF2α is as potent as PGF2α to inhibit differentiation of adipocyte precursors in primary culture and of the adipogenic cell line 1246. In the presence of 9α,11β-PGF2α, the cells remained fibroblast-like, typical of undifferentiated adipocyte precursors. Triglyceride accumulation and increase of specific activity for glycerol-3-phosphate dehydrogenase were inhibited. In addition, mRNA expression of early markers of differentiation such as lipoprotein lipase (LPL) and fatty acid binding protein (FAB) was decreased. The isomer 9β,11α-PGF2α and other PGF2α derivatives were inactive. These results provide new information on the biological activity of 9α,11β-PGF2α as an inhibitor of adipose differentiation and about the structural characteristics of prostaglandins required for maintenance of a high adipose differentiation inhibitory effect.