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At least 127 records · Page 7Linked to original sources

A truncated human peroxisome proliferator-activated receptor alpha splice variant with dominant negative activity.

The peroxisome proliferator-activated receptor alpha (PPARalpha) plays a key role in lipid and lipoprotein metabolism. However, important inter- and intraspecies differences exist in the response to PPARalpha activators. This incited us to screen for PPARalpha variants with different signaling functions. In the present study, using a RT-PCR approach a variant human PPARalpha mRNA species was identified, which lacks the entire exon 6 due to alternative splicing. This deletion leads to the introduction of a premature stop codon, resulting in the formation of a truncated PPARalpha protein (PPARalphatr) lacking part of the hinge region and the entire ligand-binding domain. RNase protection analysis demonstrated that PPARalphatr mRNA is expressed in several human tissues and cells, representing between 20-50% of total PPARalpha mRNA. By contrast, PPARalphatr mRNA could not be detected in rodent tissues. Western blot analysis using PPARalpha-specific antibodies demonstrated the presence of an immunoreactive protein migrating at the size of in vitro produced PPARalphatr protein both in human hepatoma HepG2 cells and in human hepatocytes. Both in the presence or absence of 9-cis-retinoic acid receptor, PPARalphatr did not bind to DNA in gel shift assays. Immunocytochemical analysis of transfected CV-1 cells indicated that, whereas transfected PPARalphawt was mainly nuclear localized, the majority of PPARalphatr resided in the cytoplasm, with presence in the nucleus depending on cell culture conditions. Whereas a chimeric PPARalphatr protein containing a nuclear localization signal cloned at its N-terminal localized into the nucleus and exhibited strong negative activity on PPARalphawt transactivation function, PPARalphatr interfered with PPARalphatr transactivation function only under culture conditions inducing its nuclear localization. Cotransfection of the coactivator CREB-binding protein relieved the transcriptional repression of PPARalphawt by PPARalphatr, suggesting that the dominant negative effect of PPARalphatr might occur through competition for essential coactivators. In addition, PPARalphatr interfered with transcriptional activity of other nuclear receptors such as PPARgamma, hepatic nuclear factor-4, and glucocorticoid receptor-alpha, which share CREB-binding protein/p300 as a coactivator. Thus, we have identified a human PPARalpha splice variant that may negatively interfere with PPARalphawt function. Factors regulating either the ratio of PPARalphawt vs. PPARalphatr mRNA or the nuclear entry of PPARalphatr protein should therefore lead to altered signaling via the PPARalpha and, possibly also, other nuclear receptor pathways.

Animals↗

Remodeling of the transmembrane segment in human glycophorin by aberrant RNA splicing.

This paper describes the identification in S-s-U-erythrocytes of a novel glycophorin (GP), He(P2), with structural variations in both its extracellular and transmembrane domains. In the exon II-intron 2 region, a sequence transfer from GPA to GPB, probably via the mechanism of gene conversion, was associated with the induction of multiple untemplated nucleotide replacements. These changes defined the sequence for the He epitope while concomitantly abolishing GPB-associated N antigenicity. Moreover, the GPHe(P2) gene carries two splice site mutations that coordinately affect the processing of exon V coding for the transmembrane segment. The C-->G transversion at the 3' end of exon V created a cryptic acceptor splice site, whereas the G-->T transversion at the +5 position of intron 5 altered the consensus of the donor splice site. Transcript sequencing revealed that neither site was utilized in the splicing of GPHe(P2) pre-mRNA. Rather, complete skipping of exon V and subsequent joining of exon IV to exon VI caused a shift in the open reading frame, which remodeled GPHe(P2) with an elongated new hydrophobic sequence for membrane anchoring. As a result, GPHe(P2) does not display the S and U epitopes although it still contains an intact linear sequence for the two antigens. These findings illustrate how exon and intron sequences concertedly determine the specificity of in vivo splice site selection. In addition, they pinpoint the conformational dependence of the S, s, and U antigens and the importance of the hinge region for their presentation.

Amino Acid Sequence↗

Molecular cloning of sheep T cell receptor gamma and delta chain constant regions: unusual primary structure of gamma chain hinge segments.

The primary structure of sheep T cell receptor (TcR) gamma and delta chain constant (C) regions has been determined by cDNA cloning. A comparison of the nucleotide and deduced amino acid sequences of the sheep chains with known human and mouse sequences shows that the primary structure of the immunoglobulin, transmembrane and cytoplasmic C gamma domains and all of the C delta region has been substantially conserved. However, the hinge or connector region of sheep gamma chains differs significantly from all known TcR chains. Clones representing two different sheep C gamma genes were isolated and both contain additional sequence in this region, making them the longest TcR chains so far identified. The hinge region of both sheep C gamma sequences contains two additional cysteine residues and a motif of five amino acids (TTESP or TTEPP) which has been triplicated in one of the clones. Other repetitive segments of 13-17 amino acids could also be identified suggesting that, as in the human C gamma 2 gene, this region of the sheep genes could have arisen from an exon duplication or triplication event. Southern blot analysis of sheep DNA confirmed the presence of one C delta gene and at least two C gamma genes. A restriction fragment length polymorphism that is probably associated with allelic sequence variation in the sheep C delta gene was detected in DNA from different animals. Although the essential structure of the gamma/delta TcR appears well conserved through evolution, the marked heterogeneity evident in the hinge region of gamma chains both within and between species, and particularly the presence of additional cysteine residues in the sheep sequences, may be of structural and functional importance.

Amino Acid Sequence↗

Sequence variations in the surface loop near the nucleotide binding site modulate the ATP turnover rates of molluscan myosins.

The muscle and species-specific differences in enzymatic activity between Placopecten and Argopecten striated and catch muscle myosins are attributable to the myosin heavy chain. To identify sequences that may modulate these differences, we cloned and sequenced the cDNA encoding the myosin heavy chains of Placopecten striated and catch muscle. Deduced protein sequences indicate two similar isoforms in catch and striated myosins (97% identical); variations arise by differential RNA splicing of five alternative exons from a single myosin heavy chain gene. The first encodes the phosphate-binding loop; the second, part of the ATP binding site; the third, part of the actin binding site; the fourth, the hinge in the rod; and the fifth, a tailpiece found only in the catch muscle myosin heavy chain. Both Placopecten myosin heavy chains are 96% identical to Argopecten myosin heavy chaina isoforms. Because subfragment-1 ATPase activities reflect the differences observed in the parent myosins, the motor domain is responsible for the variations in ATPase activities. In addition, data show that differences are due to Vmax and not actin affinity. The sequences of all four myosin heavy chain motor domains diverge only in the flexible surface loop near the nucleotide binding pocket. Thus, the different ATPase activities of four molluscan muscle myosins are likely due to myosin heavy chain sequence variations within the flexible surface loop that forms part of the ATP binding pocket of the motor domain.

Actins↗

MMP-28, a new human matrix metalloproteinase with an unusual cysteine-switch sequence is widely expressed in tumors.

We report the discovery, cloning, and characterization of a novel human matrix metalloproteinase (MMP-28) cDNA gene. The deduced 520-amino-acid sequence of MMP-28 includes a signal peptide, a prodomain with an unusual cysteine-switch PRCGVTD motif followed by the furin cleavage RRKKR site, a catalytic domain, a hinge-region and a hemopexin-like domain. On the basis of their structural characteristics, MMP-28 belongs to the MMP-19 subfamily. The genomic MMP-28 gene uniquely mapped to chromosome 17q11.2 includes eight exons and seven introns. The broad range of expression in carcinomas as well as normal adult and fetal tissues suggests an important functional role for MMP-28.

Alternative Splicing↗

Aberrant oestrogen receptor species in human meningioma tissue.

Meningiomas are very rich in progestin receptors (PR) whereas oestrogen receptors (ER) are seldomly found and only at low concentrations. These tumours might possess an ER which is defective in oestrogen binding but still functional in stimulating oestrogen-responsive genes such as PR. In human meningiomas a polymerase chain reaction fragment including the DNA binding domain, the hinge region and the ligand binding domain of ER was amplified. The size of the fragment obtained was as expected from wild type mRNA sequences. Moreover, a variant, which was overexpressed in meningiomas, with a major deletion in exons 2-6 was detected.

Base Sequence↗

Wild type and alternatively spliced estrogen receptor messenger RNA in human meningioma tissue and MCF7 breast cancer cells.

Human meningiomas are rich in progesterone receptors (PR), which appear to be expressed autonomously. To investigate whether estrogen receptor (ER) variants which do not bind the ligand, but may constitutively induce PR expression, prevail in meningioma, we amplified cDNA by PCR in order to detect mRNA coding for the ER in meningioma which were ER-negative/PR-positive at the protein level. We screened for a portion of the ER which includes the DNA binding domain, the hinge region and the ligand binding domain. For this part of the ER we found a wild type mRNA in all 8 meningiomas tested. No mutations were detected. Apart from this transcript we found two alternatively spliced products missing exons 4 and 7, respectively in 8/8 meningioma specimens. These two products were not exclusive for meningioma, since they were also detected in the MCF7 breast cancer cell line which was used as control. ER deletion mutants missing exon 7 have already been reported [Ref. 1; Molec. Endocr. 5 (1991) 1571-1577]. These are dominant negative. To our knowledge, this is the first report on ER mutants missing exon 4. The presence of ER variants missing exon 4, which is probably not able to bind heat shock protein 90 and therefore may be constitutively active, might explain the autonomous expression of PR in meningioma.

Alternative Splicing↗

A new class II rice chitinase, Rcht2, whose induction by fungal elicitor is abolished by protein phosphatase 1 and 2A inhibitor.

Among the four classes of chitinase, a class II chitinase had not yet been reported for rice. We have isolated and characterized a class II acidic chitinase, Rcht2, from rice (Oryza sativa L. cv. Cheongcheongbyeo). The protein consists of a single polypeptide chain of 261 amino acid residues and includes a putative signal sequence of 29 amino acids at its N-terminus. It has a calculated molecular mass of 27,642 Da and an isoelectric point of 5.56. The Rcht2 chitinase lacks the cysteine-rich and hinge domains in the N-terminal region of the protein, which is the criterion for its classification as a class II chitinase. Comparison of the genomic and the cDNA sequence revealed that the coding region of Rcht2 consist of three exons of 301, 112, and 370 bp separated by two introns of 89 and 984 bp. In suspension-cultured rice cells, the transcript level of Rcht2 was dramatically increased by treatment with both glycol chitin and fungal elicitor. The application of protein phosphatase 1 and 2A inhibitors, calyculin A and okadaic acid, effectively abolished the induction of Rcht2 in response to fungal elicitor. In contrast, the activation of Rcht2 transcript was not inhibited by both cycloheximide and protein kinase inhibitors. These results demonstrate that protein dephosphorylation events play a crucial role in the elicitor-mediated induction of Rcht2 in rice cells, while de novo protein synthesis is not required for induction.

Amino Acid Sequence↗

Isotypic variants of the interferon-inducible transcriptional repressor IFI 16 arise through differential mRNA splicing.

We recently demonstrated that IFI 16, a human member of a family of interferon-inducible nuclear proteins, can function as a potent repressor of transcription. All members of this family are found in the nucleus and contain 1 or 2 copies of a conserved 200 amino acid repeat domain. IFI 16 migrates on SDS-PAGE as three distinct protein species (IFI 16A, 16B, 16C) clustered at 85-95 kDa, and we therefore set out to determine the molecular mechanisms underpinning the production of these different isoforms. In the present report, we have used thermal cycling amplification of reverse-transcribed mRNA (RT-PCR) and Southern blotting of genomic DNA to show that the three protein isoforms result from translation of three separate mRNA species produced by differential mRNA splicing. This differential splicing gives rise to variability in the central ("hinge") domain of the molecule which separates the two 200 amino acid repeats. The longest mRNA (approximately 2.7 kb) encodes an open reading frame of 2355 bp and generates the IFI 16A isoform of 785 amino acids. It contains sequences from 11 exons, including a newly identified exon (7a) which appears to have arisen by tandem duplication of exon 7. The second isoform (IFI 16B, corresponding to the form reported previously) is the most abundantly expressed, and results from deletion of exon 7a (168 bp) to encode a protein of 729 amino acids. The smallest mRNA encodes the IFI 16C isoform (2019 bp), has deleted both exon 7 and exon 7a, and shortens the protein by a further 56 amino acids. Culture of IFI 16-expressing cells with tunicamycin and incubation of cellular lysates with endoglycosidase H suggested that neither IFI 16A nor IFI 16B is glycosylated; however, some IFI 16C molecules showed a minor degree of complex carbohydrate addition. Furthermore, immunoprecipitation and Western blotting indicated that all three IFI 16 isoforms are phosphorylated on serine and threonine residues, but not on tyrosine. Thus, the three IFI 16 protein isoforms arise due to alternative RNA splicing and not due to differential glycosylation or phosphorylation. Finally, IFI 16 isoforms can homo- and heterodimerize, and we have mapped the dimerization domain to the amino terminus which contains an imperfect leucine zipper domain.

Alternative Splicing↗

Differential expression of two estrogen receptor beta isoforms in the human fetal testis during the second trimester of pregnancy.

Testicular cancer is more common in individuals with disorders of the male reproductive tract. It has been suggested that inappropriate exposure to estrogens during fetal life may have an impact on maturation of testicular germ cells that are the cells of origin of the majority of testis cancers. The aim of the present study was to establish whether human fetal germ cells (gonocytes) are a potential target of estrogen action. To address this issue, we used RT-PCR and immunohistochemistry to examine the pattern of expression of estrogen receptors (ER alpha, ER beta, and ER beta 2 variant) in human fetal testes at 12-19 wk gestation. ER alpha, mRNA, and protein were not detected in any of the fetal testes. In contrast, using an antibody directed against the hinge domain of ER beta expression was detected in multiple testicular nuclei. RT-PCR with primers specific for full-length wild-type ER beta (ER beta 1) or the ER beta 2 variant formed by splicing of an alternative eighth exon, was performed on whole-tissue extracts and materials recovered by laser capture and revealed that mRNAs for both isoforms were expressed. Immunohistochemistry with isotype-specific monoclonal antibodies showed that ER beta 1 was low/undetectable in gonocytes, whereas these cells expressed the highest levels of ER beta 2, compared with other testicular cell types. Both ER beta 1 and ER beta 2 were detected in some but not all Sertoli cells, peritubular cells, and other interstitial cells including those tentatively identified as Leydig cells. Our immunohistochemical results demonstrate that during the second trimester, some but not all somatic cells within the human fetal testis express wild-type ER beta (ER beta 1) protein and/or the variant isoform of ER beta (ER beta 2) that lacks amino acids essential for binding of estradiol. ER beta 2 protein was readily detectable in fetal gonocytes, whereas ER beta 1 was not. We did not detect expression of ER alpha. The expression of ER beta 2, a variant proposed act as a dominant negative receptor, might prevent estrogen action in gonocytes. We suggest that during this period of fetal life, estrogenic ligands are most likely to act on somatic cells that contain ER beta 1 protein.

Estrogen Receptor alpha↗

A novel matrix metalloproteinase gene (XMMP) encoding vitronectin-like motifs is transiently expressed in Xenopus laevis early embryo development.

To study the role of matrix metalloproteinases (MMPs) in early vertebrate development, we cloned cDNAs for six different MMPs from the frog Xenopus laevis embryos at different stages of development and describe here a novel MMP called XMMP. Xenopus XMMP has 604 amino acids including a putative signal peptide of 22 residues. At the carboxyl-terminal end of the propeptide, XMMP has a 37-amino acid-long insertion domain containing a segment that is 38% identical with a rat vitronectin sequence between residues 108-135. Following this domain is an RRKR motif, a putative cleavage site for intracellular activation by furin proteinases. XMMP lacks a proline-rich linker peptide, or hinge region, typically found in other MMPs between the catalytic domain and carboxyl-terminal "hemopexin/vitronectin-like" domain. In XMMP, the carboxyl-terminal domain is composed of four tandem repeats that are 21-33% identical to a sequence (residues 213-264) encoded by vitronectin exon-5. Interestingly, XMMP gene is transiently expressed during Xenopus embryo development. XMMP mRNA of 3.0 kilobase pairs was undetected in the blastula stage embryo, induced in gastrula embryo, expressed in neurula embryo, and then down-regulated in pretailbud embryo. In comparison, other Xenopus MMP genes that we have cloned show a different developmental regulation. In blastula embryo, the only MMP gene expressed was found to be 92-kDa type IV collagenase, which was also expressed in the gastrula, neurula, and pretailbud embryos. Expression of stromelysin-1, stromelysin-3, and two different membrane type-MMPs was first detected in the neurula and pretailbud embryos. These results suggest that MMPs and the novel XMMP reported here play a role in Xenopus early development.

Amino Acid Sequence↗

Structure and organization of the human ankyrin-1 gene. Basis for complexity of pre-mRNA processing.

Ankyrin-1 (ANK-1) is an erythrocyte membrane protein that is defective in many patients with hereditary spherocytosis, a common hemolytic anemia. In the red cell, ankyrin-1 provides the primary linkage between the membrane skeleton and the plasma membrane. To gain additional insight into the structure and function of this protein and to provide the necessary tools for further genetic studies of hereditary spherocytosis patients, we cloned the human ANK-1 chromosomal gene. Characterization of the ANK-1 gene genomic structure revealed that the erythroid transcript is composed of 42 exons distributed over approximately 160 kilobase pairs of DNA. Comparison of the genomic structure with the protein domains reveals a near-absolute correlation between the tandem repeats encoding the membrane-binding domain of ankyrin with the location of the intron/exon boundaries in the corresponding part of the gene. Erythroid stage-specific, complex patterns of alternative splicing were identified in the region encoding the regulatory domain of ankyrin-1. Novel brain-specific transcripts were also identified in this region, as well as in the "hinge" region between the membrane-binding and spectrin-binding domains. Utilization of alternative polyadenylation signals was found to be the basis for the previously described, stage-specific 9.0- and 7.2-kilobase pair transcripts of the ANK-1 gene.

Alternative Splicing↗

Novel androgen receptor gene mutations in Australian patients with complete androgen insensitivity syndrome.

We have identified androgen receptor (AR) gene mutations in eight Australian subjects with complete androgen insensitivity syndrome (AIS). Four individuals, from three families, have novel mutations that introduce premature termination codons. Two siblings have the nonsense mutation Glu681X, and another subject has the nonsense mutation p.Ser884X. The other subject has a CA insertion at codon 829 (c.2847_2848insCA), causing a frameshift mutation that introduces four nonsense amino acids prior to a Stop codon. All the termination codons occur in the ligand binding domain, and cause reduced androgen binding in patient genital skin fibroblasts. Four further patients have missense mutations. One subject has two different mutations, p.Ala645Asp in the hinge region of the receptor, and p.Arg752Gln in the ligand binding domain. Both these mutations have previously been reported in patients with AIS, but the combination of these two mutations in one subject is unique. Another subject has a novel c.2533G>C transversion at the first nucleotide in exon 5, introducing the amino acid change p.Gly724Ala at a highly conserved residue in the ligand binding domain. Androgen binding is normal in fibroblasts from this subject, although other point mutations at this amino acid totally abolish binding. Two other subjects have mutations previously described as causing AIS, namely p.Arg779Trp and p.Val889Met substitutions in the ligand binding domain of the receptor. The p.Arg779Trp mutation is associated with the detection of a truncated AR protein in this patient's fibroblasts, suggesting the mutation renders the receptor susceptible to proteolysis.

Adult↗

Molecular characterization of Gm(n+) and G2m(n-) allotypes.

Immunoglobulin (Ig) allotype typing is usually performed with serological methods based on hemagglutination inhibition. The recent development of molecular techniques has allowed the molecular typing of several Ig markers. The hinge, CH2, and CH3 domains of the G2 gene from six unrelated individuals (three G2m(n+) and three G2m(n-)) were amplified and cloned to establish the molecular basis of the G2mn+ and G2mn- . Comparison of the allele sequences revealed three changes: two (codons 308 and 437) are silent exonic substitutions, one is a G to A transition corresponding to an amino acid difference in position 282: Val (GTG) in G2mn- , Met (ATG) in G2mn+ . These substitutions were identified via two approaches: 282 polymorphism, after digestion of a specific polymerase chain reaction product with Nla III followed by acrylamide electrophoresis; 308 and 437, by a dot-blot technique using allele-specific oligonucleotides. These molecular typing results correspond exactly to those obtained serologically; moreover, the three substitutions defining the G2mn+ and G2mn- alleles are always associated in a strict linkage disequilibrium.

Base Sequence↗

Five new families with resistance to thyroid hormone not caused by mutations in the thyroid hormone receptor beta gene.

Resistance to thyroid hormone (RTH) is a syndrome of variable tissue hyposensitivity to TH. In 191 families, the RTH phenotype has been linked to mutations located in the ligand-binding or hinge domains of the TH receptor (TR) beta gene. The defective TRbeta molecules interfere with the function of the normal TRs to produce dominantly inherited RTH. Of the 65 families with RTH studied in our laboratory, 59 had mutations in the mutagenic region of the TRbeta gene that encompasses exons 7-10. Isolation of a TRbeta PAC (P1 derived artificial chromosome) clone provided the intronic sequences necessary to amplify and sequence the entire TRbeta gene from genomic DNA. Not a single nucleotide substitution, deletion, or insertion was found in all coding and noncoding TRbeta1- and TRbeta2-specific and common exons of the five families with RTH reported herein. Furthermore, linkage analysis using polymorphic markers excluded involvement of the TRbeta and TRalpha genes in two and three of the five families, respectively. The phenotype of RTH in patients without TRbeta gene defects was not different from that in patients with RTH due to TRbeta gene mutations in terms of clinical presentation and reduced responsiveness of the pituitary and peripheral tissues to TH. However, the degree of thyrotroph hyposensitivity to TH appeared to be among the more severe, similar to that of patients with mutant TRbetas that have more than 50-fold reduction of T3 binding affinity and strong dominant negative effect. In these five families and another with non-TRalpha/non-TRbeta RTH, previously identified in our laboratory, evidence for dominant inheritance was secured in two families, and the appearance of a new defect or recessive inheritance was found in the remaining four families. RTH without a structural TRbeta defect occurs in about 10% of families expressing the classic phenotype of TH hyposensitivity, and TRbeta and TRalpha gene involvement has been excluded in 5%. We postulate that a cofactor that interacts with TR is potentially responsible for the manifestation of RTH in these families. As affected subjects are not infertile, the high prevalence of putative neomutations and the low rate of transmission in this non-TR form of RTH may be due to reduced survival of embryos harboring the defect.

Adult↗

A new human MR splice variant is a ligand-independent transactivator modulating corticosteroid action.

Aldosterone effects are mediated by the MR, which possesses the same affinity for mineralocorticoids and glucocorticoids. In addition to the existence of mechanisms regulating intracellular hormone availability, we searched for human MR splice variants involved in tissue-specific corticosteroid function. We have identified a new human MR isoform, hMRDelta5,6, resulting from an alternative splicing event skipping exons 5 and 6 of the human MR gene. hMRDelta5,6 mRNAs are expressed in several human tissues at different levels compared with wild-type human MR, as shown by real time PCR. Introduction of a premature stop codon results in a 75-kDa protein lacking the entire hinge region and ligand binding domain. Interestingly, hMRDelta5,6 is still capable of binding to DNA and acts as a ligand-independent transactivator, with maximal transcriptional induction corresponding to approximately 30-40% of aldosterone-activated wild-type human MR. Coexpression of hMRDelta5,6 with human MR or human GR increases their transactivation potential at high doses of hormone. Finally, hMRDelta5,6 is able to recruit the coactivators, steroid receptor coactivator 1, receptor interacting protein 140, and transcription intermediary factor 1alpha, which enhance its transcriptional activity. Ligand-independent transactivation and enhancement of both wild-type MR and GR activities by hMRDelta5,6 suggests that this new variant might play a role in modulating corticosteroid effects in target tissues.

Adrenal Cortex Hormones↗

Characteristic sequences in the upstream region of the human tyrosinase gene.

A human tyrosinase gene containing a 5'-flanking region and the first exon was isolated from a normal human liver library using mouse tyrosinase cDNA as a probe for screening. In the 5'-upstream region of transcriptional start sites, there is a putative TATA box and CAAT box and some palindromic sequences. A characteristic sequence of (GA:TCn, which can assume a hinged-DNA structure, was present from -869 nt to -633 nt in this 5'-flanking region.

Albinism↗

Molecular cloning and sequence analysis of the mouse protein C inhibitor gene.

The gene encoding mouse protein C inhibitor (mPCI) was isolated and its nucleotide sequence determined. Alignment of the genomic sequence with that of a cDNA obtained from mouse testis revealed that the mPCI gene (like the human counterpart) is composed of five exons and four introns with highly conserved exon/intron boundaries. It encodes a pre-polypeptide of 405 amino acids, which shows 63% identity with human PCI (hPCI). The putative reactive site is identical to that of hPCI from P5 to P3', suggesting a similar protease specificity. Also the putative heparin binding sites and 'hinge' regions are highly homologous in mouse and hPCI.

Amino Acid Sequence↗