Homology analysis of BmREEPa.

<p>(A) Sequence analysis of BmREEPa. Black color represents the TB2/DP1, HVA22 domain; red represents transmembrane domain; (B) phylogenetic tree (N-J) of BmREEPa with REEP genes from vertebrates and invertebrates.</p

Effect of BmNPV transduction in <i>BmREEPa</i>-RNAi BmN-SWU1 cells.

<p>(A) Green fluorescence in cells at 48 h post-infection with v39K^prm-eGFP BVs; (B) Analysis of <i>VP39</i> expression in BmN-SWU1 48 h after infection with v39K^prm-eGFP BVs; (C) Viral titer in cell culture fluid 48 h after infection with v39K^prm-eGFP BVs. BmN-SWU1 without v39K^prm-eGFP BVs, BmN-SWU1 with v39K^prm-eGFP BVs and DsRed-RNAi with v39K^prm-eGFP BVs were used as controls; * indicates significant differences at P < 0.05, ** indicates significant differences at P < 0.01 with respect to the control.</p

BmREEPa localization and topology model.

<p>(A) BmREEPa full-length, N-terminal and C-terminal sequence localization; (B) Western blot of full-length BmREEPa in the isolated membrane and cytosol proteins; (C) Western blot of BmN-SWU1 cells and culture fluid expressing BmREEPa N- and C-termini; (D) Topology model of BmREEPa. BmREEPa-L, BmREEPa-S, BmREEPa-N terminus and BmREEPa-C terminus were co-expressed with Flag tags and DsRed. DsRed was used as a marker in fluorescence observation while anti-Flag antibody was used in Western blots.</p

Effect of BmNPV transduction in BmN-SWU2 cells over-expressing <i>BmREEPa</i>.

<p>(A) Green fluorescence in cells infected with v39K^prm-eGFP BVs; (B) Analysis of <i>VP39</i> expression in cells 48 h after infection with v39K^prm-eGFP BVs; (C) Viral titer in cell culture fluid at 48 h post-infection with v39K^prm-eGFP BVs. BmN-SWU2 without v39K^prm-eGFP BVs, BmN-SWU2 with v39K^prm-eGFP BVs and with v39K^prm-eGFP BVs were used as controls; * indicates significant differences at P < 0.05, ** indicates significant differences at P < 0.01 when compared to the control.</p

Proteins differently expressed between BmN-SWU1 and BmN-SWU2 via proteomic analysis.

<p>(A) GO categories of differently expressed proteins between BmN-SWU1 and BmN-SWU2. A ratio of BmN-SWU2/BmN-SWU1 ≥ 1.5 was considered as up-regulated (brown bar) and ≤ 0.66 was considered down-regulated (purple bar); (B) classification of KEGG pathways associated with the differentially expressed proteins between BmN-SWU1 and BmN-SWU2. The ratio of BmN-SWU2/BmN-SWU1 ≥1.5 was considered up-regulated (brown bar) and ≤ 0.66 was considered down-regulated (blue bar).</p

Two different splicesomes of <i>BmREEPa</i>.

<p>(A) Gene structure of two <i>BmREEPa</i> splicesomes. The red region is lacking in <i>BmREEPa</i>-S. (B) Differences between the gene sequences of the two <i>BmREEPa</i> splicesomes; the sequence in red is not present in <i>BmREEPa</i>-S; black underline represents the start and stop codons.</p

Identification and characterization of the BmCyclin L1-BmCDK11A/B complex in relation to cell cycle regulation

<p>Cyclin proteins are the key regulatory and activity partner of cyclin-dependent kinases (CDKs), which play pivotal regulatory roles in cell cycle progression. In the present study, we identified a <i>Cyclin L1</i> and 2 CDK11 2 CDK11 splice variants, <i>CDK11A</i> and <i>CDK11B</i>, from silkworm, <i>Bombyx mori</i>. We determined that both Cyclin L1 and CDK11A/B are nuclear proteins, and further investigations were conducted to elucidate their spatiofunctional features. Cyclin L1 forms a complex with CDK11A/B and were co-localized to the nucleus. Moreover, the dimerization of CDK11A and CDK11B and the effects of Cyclin L1 and CDK11A/B on cell cycle regulation were also investigated. Using overexpression or RNA interference experiments, we demonstrated that the abnormal expression of Cyclin L1 and CDK11A/B leads to cell cycle arrest and cell proliferation suppression. Together, these findings indicate that CDK11A/B interacts with Cyclin L1 to regulate the cell cycle.</p