Characterization of a protamine gene from the chum salmon (Oncorhynchus keta)

Anti-Obesity and Hypocholesterolemic Actions of Protamine-Derived Peptide RPR (Arg-Pro-Arg) and Protamine in High-Fat Diet-Induced C57BL/6J Mice

Dietary protamine can ameliorate hyperlipidemia; however, the protamine-derived active peptide and its hypolipidemic mechanism of action are unclear. Here, we report the discovery of a novel anti-obesity and hypocholesterolemic peptide, RPR (Arg-Pro-Arg), derived from protamine in mice fed a high-fat diet for 50 days. Serum cholesterol levels were significantly lower in the protamine and RPR groups than in the control group. White adipose tissue weight was significantly decreased in the protamine and RPR groups. The fecal excretion of cholesterol and bile acid was significantly higher in the protamine and RPR groups than in the control group. We also observed a significant decrease in the expression of hepatic SCD1, SREBP1, and adipocyte FAS mRNA, and significantly increased expression of hepatic PPARα and adipocyte PPARγ1 mRNA in the protamine group. These findings demonstrate that the anti-obesity effects of protamine are linked to the upregulation of adipocyte PPARγ1 and hepatic PPARα and the downregulation of hepatic SCD1 via SREBP1 and adipocyte FAS. RPR derived from protamine has a crucial role in the anti-obesity action of protamine by evaluating the effective dose of adipose tissue weight loss.

Characterization of Protamine as a Transfection Accelerator for Gene Delivery

Protamine is an FDA-approved compound with a documented safety profile that facilitates efficient plasmid condensation for gene delivery by various types of cationic liposomes. It also improves adenoviral vector-mediated gene transfer as a transfection accelerator. However, there is no consensus as to the mechanism of protamine on gene delivery into cells. To analyze the uptake and subcellular distribution, plasmid and protamine were labeled with FITC and Texas-Red, respectively. Although the uptake of FITC-labeled plasmid/protamine complexes into the cells was the same as that of free FITC-labeled plasmid in HeLa, SOJ and A549 cells, they improved the transfection efficiency by several orders of magnitude. Moreover, we found that protamine derived from different sources (salmon, herring and trout sperm) had different transfection efficiencies; however, the gene transfer efficiency with protamine was lower than with optimized poly(L-lysine) and DEAE-Dextran. There were likely two main reasons: firstly, the uptake of plasmid mediated by protamine was complete within the first 10min because the particle size increased as time passed, and secondly, the plasmid/protamine complexes were not released from endosomal membrane. These results indicate that as a transfection accelerator from an appropriate protamine source, with controlled particle size and facile release from endosomes would lead to successful gene delivery with protamine.

Water-Borne Endovascular Embolics Inspired by the Undersea Adhesive of Marine Sandcastle Worms

Transcatheter embolization is used to treat vascular malformations and defects, to control bleeding, and to selectively block blood supply to tissues. Liquid embolics are used for small vessel embolization that require distal penetration. Current liquid embolic agents have serious drawbacks, mostly centered around poor handling characteristics and toxicity. In this work, a water-borne in situ setting liquid embolic agent is described that is based on electrostatically condensed, oppositely charged polyelectrolytes-complex coacervates. At high ionic strengths, the embolic coacervates are injectable fluids that can be delivered through long narrow microcatheters. At physiological ionic strength, the embolic coacervates transition into a nonflowing solid morphology. Transcatheter embolization of rabbit renal arteries demonstrated capillary level penetration, homogeneous occlusion, and 100% devascularization of the kidney, without the embolic crossing into venous circulation. The benign water-borne composition and setting mechanism avoids many of the problems of current liquid embolics, and provides precise temporal and spatial control during endovascular embolization.

Targeting bacterial endotoxin: two sides of a coin

The term sepsis describes a potentially lethal clinical condition that develops as a result of a dysregulated host response to bacterial infection. The most common bacterial component implicated in initiating the septic syndrome is a cell wall molecule derived from Gram-negative bacteria, known as lipopolysaccharide (LPS) or endotoxin. Like all mammals, humans are equipped with an LPS-sensing machinery consisting, primarily, of LPS-binding protein (LBP), CD14, a glycosylphosphatidylinositol (GPI)-anchored monocyte differentiation antigen, and toll-like receptor 4 (TLR4), a signal-transducing integral membrane protein. Modest stimulation of TLR4 facilitates the elimination of invading microorganisms. Potent TLR4 stimulation, however, produces severe reactions in the host, often leading to multiple organ failure and death. The search for pharmaceuticals that reduce mortality in septic patients has been a painstaking process. Thus far, only a few compounds have been found to significantly reduce mortality rates. Perhaps one of the more promising therapeutic strategies currently pursued is based on the identification of synthetic or naturally occurring substances that neutralize LPS or inhibit LPS-mediated activation of host immune cells, such as monocytes and macrophages. Here, we describe a number of diverse molecular structures with a capacity to either enhance or blunt LPS-induced monocyte activation. The underlying molecular mechanisms are discussed.

Sperm nuclear basic proteins of two closely related species of Scorpaeniform fish (Sebastes maliger, Sebastolobus sp.) with different sexual reproduction and the evolution of fish protamines

In this paper, we present a review of sperm nuclear basic proteins (SNBPs) in teleost fish. The distribution of the three basic groups of SNBPs [histone (H)-type, protamine-like (PL)-type and protamine (P)-type], their evolution and possible relation to the mode of fertilization are described. In this regard, we have characterized the SNBPs from two closely related species of Scorpaeniform fish: internally fertilizing Sebastes maliger and externally fertilizing Sebastolobus sp., both in the family Scorpaenidae. Despite the different reproductive behavior of these two closely related rockfish species, in both instances the SNBP consists of protamines. However, there is a significant increase in the arginine content of the protamine in the internally fertilizing rockfish. The relevance of this observation is discussed within the context of the P-type SNBP in teleosts. The rapid evolution of teleost protamines, including those in rockfish, has also allowed us to obtain a molecular phylogeny for this group of bony fish that is almost indistinguishable from that currently available from the use of conventional anatomical/paleontological markers.

Enrichment of middle repetitive element Bm-1 transcripts in translationally active RNA fractions of the silkmoth, Bombyx mori

The Bm-1 repetitive element family represents a group of transcribed repetitive sequences in the genome of the silkmoth Bombyx mori. In the Bm-5 and BmN permanent cell lines studied here, alpha-amanitin inhibition and nuclear 'run-on' experiments demonstrated that approximately 80% of the Bm-1 transcripts are produced by RNA polymerase II. Bm-1 transcripts are dramatically enriched in poly A+ and polysomal RNA fractions compared to total RNA in these two cell lines. In the Bm-5 cell line, from total to poly A+ and polysomal RNA fractions, Bm-1 transcripts are enriched approximately 4 and 2 times, respectively, while in the BmN cell line these same fractions are enriched about 2 and 19 times compared to total RNA. This suggests that the Bm-1 transcripts may be involved in post-transcriptional processes or control of translation. Our data also revealed less size heterogeneity of Bm-1 transcripts in polysomal as compared to nuclear fractions. In the Bm-5 and BmN cell lines, the size of most transcripts containing Bm-1 sequences increases from approximately 1700 nt in the nucleus to 3000 nt in the polysomal fraction, both fractions with RNA much larger than the Bm-1 consensus sequence (250 bp). This raises the possibility that some Bm-1 elements are transcribed as part of larger transcripts containing mRNA by way of 'read-through', and may be involved in post-transcriptional regulation of gene expression as cis and/or trans acting elements.

Amino acid sequences of P1 protamines and the phylogeny of eutherian mammals: a cladistic study

Amino acid and cDNA sequences of eutherian P1 protamines, known from publications of other authors, were compared by a cladistic method. Fish, toad and bird protamines were used for the pertinent "outgroup comparisons", i.e. they provided relevant data for the comparative alignment of the sequences and for the recognition of evolutionary trends. In the sequence positions compared, each amino acid was individually assigned as a plesiomorphic or apomorphic character state (qualitative treatment). The resulting phylogenetic tree (Fig. 2) is only partially in accordance with common ideas on eutherian phylogeny. Disagreements refer to the branching points of Perissodactyla, Lagomorpha and Rodentia.

On the evolution of protamines in bony fish: alternatives to the "retroviral horizontal transmission" hypothesis

Fish protamines are highly specialized molecules which are responsible for chromatin condensation during the last stages of spermatogenesis (spermiogenesis). However, not all fish contain protamines in their sperm nuclei; rather, there seems to be a random distribution of protamines within this group. The origin of this sporadic presence of protamines in the sperm and its significance have not yet been precisely determined. In this paper we have conducted an exhaustive survey of the literature available on the different types of nuclear protein composition of the sperm of teleost fish in order to try to correlate these data with what is presently known about the taxonomy of this group. The results of this analysis have allowed us to make the following observations. The divergence between protamines and histones has occurred several times during the evolution of the bony fish. However, the relative frequency of this divergence is almost negligible during the differentiation of genera and species (intrafamily variation) and is very small during the differentiation of families (interfamily variation). Nevertheless, the divergence is very noticeable among the different orders. It is therefore possible to conclude from all this that the sporadic distribution of protamines in bony fish is not a random event as initially believed. Furthermore, such a heterogeneous distribution of protamines cannot be easily accounted for by a mechanism of horizontal retroviral transmission through repeated and independent acquisition of a protamine gene as has been recently proposed (Jankowski, Stater, Dixon (1986) J Mol Evol 23:1-10). Rather, it could possibly be explained by a repeated and independent loss of the expression of the protamine gene (or loss of the gene itself) which mainly occurred during the diversification of the orders of this group.

Purification and analysis of the major components of chum salmon protamine contained in insulin formulations using high-performance liquid chromatography

A simple high-performance liquid chromatographic method has been developed for the rapid purification and analysis of protamine components contained in insulin formulations. Only a single step is needed to separate peptides whose compositions, sizes, and unusual isoelectric points (pI 13.8) are nearly identical. The method involves their isocratic separation on a reversed-phase column using a pH 2 phosphate buffer and a low acetonitrile content as an eluant. The purified chum salmon components were analyzed by amino acid analysis, solid-phase amino acid sequencing, carboxypeptidase B digests, insulin complexation analysis, and a mass spectrophotometric procedure which gives an accurate mass of the intact peptides. This HPLC purification technique may also be applicable to protamines and other highly basic peptides isolated from other sources.

Vertebrate protamine gene evolution I. Sequence alignments and gene structure

The availability of the amino acid sequence for nine different mammalian P1 family protamines and the revised amino acid sequence of the chicken protamine galline (Oliva and Dixon 1989) reveals a much close relationship between mammalian and avian protamines than was previously thought (Nakano et al. 1976). Dot matrix analysis of all protamine genes for which genomic DNA or cDNA sequence is available reveals both marked sequence similarities in the mammalian protamine gene family and internal repeated sequences in the chicken protamine gene. The detailed alignments of the cis-acting regulatory DNA sequences shows several consensus sequence patterns, particularly the conservation of a cAMP response element (CRE) in all the protamine genes and of the regions flanking the TATA box, CAP site, N-terminal coding region, and polyadenylation signal. In addition we have found a high frequency of the CA dinucleotide immediately adjacent to the CRE element of both the protamine genes and the testis transition proteins, a feature not present in other genes, which suggests the existence of an extended CRE motif involved in the coordinate expression of protamine and transition protein genes during spermatogenesis. Overall these findings suggest the existence of an avian-mammalian P1 protamine gene line and are discussed in the context of different hypotheses for protamine gene evolution and regulation.

A new family of repetitive, retroposon-like sequences in the genome of the rainbow trout

We have identified a new family of interspersed, moderately repetitive DNA elements, termed the RSg-1 family, in the genome of the rainbow trout. Two of the elements examined here are situated upstream of sequences which code for trout nuclear proteins; a protamine gene (p101) and the clustered histone H4 gene. Sequence comparison of various RSg-1 elements indicated a high degree of nucleotide sequence homology between different members of the family. These repetitive elements exhibit well defined 3' ends which contain poly(A) segments preceded by the consensus polyadenylation signal AATAAA. Sequences flanking the 3' end of the poly(A) tract also conform to a consensus sequence. A similar sequence is also found flanking the 5' terminus of the element in the protamine clone p101, and thus may represent a target-site duplication generated upon insertion of the element into the genome. These characteristics, together with the heterogeneous nature of the 5' ends of the elements, are reminiscent of processed pseudogenes and retroposons such as the mammalian L1 family of interspersed repetitive elements.