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PubMed2003

[DRG-based cost analysis of inpatient conservative treatment of stage III/IV peripheral arterial occlusive disease].

UNLABELLED: DRG-based cost analysis of inpatient conservative treatment of PAD stage III/IV BACKGROUND: In a prospective study carried out by the German Society of Angiology and the DRG Competence Center, Munich, the question was investigated whether the costs of conservative treatment of patients with PAOD stage III/IV (DRG F65) are adequately represented within the current G-DRG system. METHODS UND PATIENTS: Between September 1 and December 16, 2002, a total of 704 patients with DRG F65 (peripheral vascular diseases) were evaluated at 8 angiologic centers in Germany. Apart from the length of hospital stay, the total costs (cost equivalents) were calculated using a method developed by the DRG Research Group at the University of Münster. Moreover, the study population was compared with a German calculation sample for the DRGs F65A/B, as published by InEK. RESULTS: As it turned out, conservatively treated patients with PAOD stage III or IV (DRGs F65A/B) cause significantly (p < 0.001) higher costs and have significantly (p < 0.001) greater lengths of hospital stay than patients who were also assigned to DRG F65 because of other vascular diseases. At the same time it became clear that angiologic centers treat twice as many patients with critical limb ischemia in comparison with the German average. The reimbursement hitherto estimated by InEK covers not even half the cost actually produced by conservative treatment of PAD stage III/IV. CONCLUSION: To ensure a performance-related reimbursement, a new basis DRG for patients with PAD stage III/IV has to be created, as has ben proposed by the German Society of Angiology. Otherwise, adequate conservative therapy in accordance with existing guidelines, of patients who cannot be treated surgically or interventionally will not be possible any more in the future.

Arterial Occlusive Diseases↗
PubMed1993

A conserved helix motif complements the protein kinase core.

Residues 40-300 of the mammalian catalytic (C) subunit of cAMP-dependent protein kinase define a conserved bilobal catalytic core shared by all eukaryotic protein kinases. Contiguous to the core is an extended amphipathic alpha-helix (A helix). Trp30, a prominent feature of this helix, fills a deep hydrophobic pocket between the two lobes on the surface opposite to the active site. The C subunit in Dictyostelium discoideum shows sequence conservation of residues 40-350 with the mouse enzyme but contains an N-terminal extension of 332 residues. A sequence corresponding to the A helix contiguous to the core is absent. However, we have now identified a remote A-helix motif (residues 77-98). When the core of the Dictyostelium C subunit was modeled, based on the mouse C subunit, complementarity between this putative A helix and the surface of the core was found to be conserved. Analysis of other protein kinases reveals that the A-helix motif is not restricted to cAMP-dependent protein kinase. In the Src-related family of protein kinases, for example, an A helix is very likely contiguous to the core, thus serving as a linker between the conserved catalytic core and the Src homology 2 domain. We predict that an A-helix motif complementary to the core will be a conserved feature of most eukaryotic protein kinases.

Amino Acid Sequence↗
PubMed2003

The Swedish Two-County Trial of mammographic screening: cluster randomisation and end point evaluation.

BACKGROUND: The Swedish Two-County Trial has been criticised on the grounds of the cluster randomisation and alleged bias in classification of cause of death. PATIENTS AND METHODS: In the Two-County Trial, 77 080 women were randomised to regular invitation to screening (active study population, ASP) and 55 985 to no invitation (passive study population, PSP), in 45 geographical clusters. After approximately 7 years, the PSP was invited to screening and the trial closed. We analysed data using hierarchical statistical models to take account of cluster randomisation, and performed a conservative analysis assuming a systematic difference between ASP and PSP in baseline breast cancer mortality in one of the counties. We also analysed deaths from causes other than breast cancer and from all causes among breast cancer cases diagnosed in the ASP and PSP. RESULTS: Taking account of the cluster randomisation there was a significant 30% reduction in breast cancer mortality in the ASP. Conservatively, assuming a systematic difference between ASP and PSP clusters in baseline breast cancer mortality, there was a significant 27% reduction in mortality in the ASP. Ignoring classification of cause of death, there was a significant 13% reduction in all-cause mortality in breast cancer cases in the ASP. CONCLUSIONS: Breast cancer mortality is a valid end point and mammographic screening does indeed reduce mortality from breast cancer. The criticisms of the Swedish Two-County Trial are unfounded.

Adult↗
PubMed2006

Array2BIO: from microarray expression data to functional annotation of co-regulated genes.

BACKGROUND: There are several isolated tools for partial analysis of microarray expression data. To provide an integrative, easy-to-use and automated toolkit for the analysis of Affymetrix microarray expression data we have developed Array2BIO, an application that couples several analytical methods into a single web based utility. RESULTS: Array2BIO converts raw intensities into probe expression values, automatically maps those to genes, and subsequently identifies groups of co-expressed genes using two complementary approaches: (1) comparative analysis of signal versus control and (2) clustering analysis of gene expression across different conditions. The identified genes are assigned to functional categories based on Gene Ontology classification and KEGG protein interaction pathways. Array2BIO reliably handles low-expressor genes and provides a set of statistical methods for quantifying expression levels, including Benjamini-Hochberg and Bonferroni multiple testing corrections. An automated interface with the ECR Browser provides evolutionary conservation analysis for the identified gene loci while the interconnection with Crème allows prediction of gene regulatory elements that underlie observed expression patterns. CONCLUSION: We have developed Array2BIO - a web based tool for rapid comprehensive analysis of Affymetrix microarray expression data, which also allows users to link expression data to Dcode.org comparative genomics tools and integrates a system for translating co-expression data into mechanisms of gene co-regulation. Array2BIO is publicly available at http://array2bio.dcode.org.

Algorithms↗
PubMed2005

Magmas gene structure and evolution.

Magmas is a nuclear encoded protein found in the mitochondria of mammalian cells. It participates in granulocyte-macrophage-colony stimulating factor (GM-CSF) signaling in hematopoietic cells and has an essential role in invertebrate development. In order to characterize the protein structural features and gene evolution of Magmas, a dataset containing 61 Magmas homologs from 52 species distributed among animals, plants and fungi was analyzed. All Magmas members were found to possess three novel sequence motifs in addition to a conserved leader peptide. Phylogenetic tree and dN/dS rate ratios showed that Magmas was evolutionarily conserved. Analysis of Magmas gene organization demonstrated incremental intron acquisition in plants and vertebrates. Significant genetic diversity in Magmas was observed from kingdom specific amino acid signatures, the presence of predicted signal peptides that target the protein to other intracellular locations besides the mitochondria, and the detection of multiple isoforms in higher animals. These studies demonstrate that Magmas members constitute an important family of conserved proteins having multifunctional activities, and provide a basis for future experiments.

Alternative Splicing↗
PubMed2002

The murine COMP (cartilage oligomeric matrix protein) promoter contains a potent transcriptional repressor region.

OBJECTIVE: A subgroup of patients with pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED) have been found to harbor mutations within the cartilage oligomeric matrix protein (COMP) gene. These two diseases are autosomal dominant disorders that are characterized by an early onset of osteoarthritis (OA). The COMP gene is expressed primarily in chondrocytes in articular cartilage as well as in tendon and ligament. Therefore, control over tissue specific COMP expression may be an important aspect in cartilage biology. To begin an analysis of the regulation of COMP expression, we have cloned, sequenced and characterized the entire genomic clone for mouse COMP that includes the COMP promoter. METHODS AND RESULTS: The COMP coding region spans 19 exons over approximately 8.4 kb of DNA. The arrangement and size of the exons have a remarkable similarity to those of the human COMP genomic sequence, indicating a significant degree of genomic conservation. Analysis of a 453 basepair region of the putative COMP promoter reveals two strong transcriptional repressor elements located between position -356 and -304 and between -251 and -180, relative to the start site for transcription. These repressor elements down-regulate transcription from the promoter in a broad spectrum of cell lines. Removal of the repressor DNA sequence from the COMP promoter leads to significant enhancement in transcriptional activity, indicating that this region acts in a dominant manner to transcriptional activators located more proximal to the start site of transcription. This region also represses transcription when linked to a heterologous promoter. CONCLUSIONS: This repressor region probably down-regulates transcription from the COMP promoter in vivo. It may help to repress transcription of COMP in non-cartilaginous tissues and/or may aid in the expression of COMP to the appropriate level in tissues such as cartilage, tendon and ligament.

Achondroplasia↗
PubMed2004

Commitment and nucleation in the protein G transition state.

An accurate characterization of the transition state ensemble (TSE) is central to furthering our understanding of the protein folding reaction. We have extensively tested a recently reported method for studying a protein's TSE, utilizing phi-value data from protein engineering experiments and computational studies as restraints in all-atom Monte Carlo (MC) simulations. The validity of interpreting experimental phi-values as the fraction of native contacts made by a residue in the TSE was explored, revealing that this definition is unable to uniquely specify a TSE. The identification of protein G's second hairpin, in both pre and post-transition conformations demonstrates that high experimental phi-values do not guarantee a residue's importance in the TSE. An analysis of simulations based on structures restrained by experimental phi-values is necessary to yield this result, which is not obvious from a simplistic interpretation of individual phi-values. The TSE that we obtain corresponds to a single, specific nucleation event, characterized by six residues common to all three observed, convergent folding pathways. The same specific nucleus was independently identified from computational and experimental data, and "Conservation of Conservation" analysis in the protein G fold. When associated strictly with complete nucleus formation and concomitant chain collapse, folding is a well-defined two state event. Once the nucleus has formed, the folding reaction enters a slow relaxation process associated with side-chain packing and small, local backbone rearrangements. A detailed analysis of phi-values and their relationship to the transition state ensemble allows us to construct a unified theoretical model of protein G folding.

Models, Molecular↗
PubMed2007

Verbal fluency in HIV infection: a meta-analytic review.

Given the largely prefrontostriatal neuropathogenesis of HIV-associated neurobehavioral deficits, it is often presumed that HIV infection leads to greater impairment on letter versus category fluency. A meta-analysis of the HIV verbal fluency literature was conducted (k = 37, n = 7110) to assess this hypothesis and revealed generally small effect sizes for both letter and category fluency, which increased in magnitude with advancing HIV disease severity. Across all studies, the mean effect size of category fluency was slightly larger than that of letter fluency. However, the discrepancy between category and letter fluency dissipated in a more conservative analysis of only those studies that included both tests. Thus, HIV-associated impairments in letter and category fluency are of similar magnitude, suggesting that mild word generation deficits are evident in HIV, regardless of whether traditional letter or semantic cues are used to guide the word search and retrieval process.

Acquired Immunodeficiency Syndrome↗
PubMed1981

Transcriptional analysis of interspersed repetitive polymerase III transcription units in human DNA.

The template for RNA polymerase III in vitro transcription found on the human DNA clone pJP53 was shown in the previous paper to enclose a member of the Alu famiy of interspersed repetitive DNA sequences. We have mapped this transcript onto its template in greater detail by comparison of the template DNA sequence to the base composition of the Tl ribonuclease digestion products of the in vitro transcript. We find that the 5' end of the transcript lies in close proximity to the 5' end of the conserved Alu family sequence as analyzed in the preceding paper. The 3' end of the transcript appears to terminate in a U-rich region beyond the region of Alu family sequence conservation. Analysis of cellular RNA by Northern blotting and hybridization with a DNA probe derived from another Alu family transcription template demonstrates abundant representation of sequences homologous to the reiterated DNA. Cytoplasmic, nonpolyadenylated RNA from human and murine cells contains a monodisperse, 300 nucleotide species, recently determined by Weiner (4) to be the 7S RNA. In contrast, the Alu-homologous transcripts are heterodisperse in mRNA and hnRNA, with the highest specific representation of Alu family sequences being found in oligo(dT)-retained hnRNA.

Animals↗
PubMed2001

Mutational and kinetic evaluation of conserved His-123 in dual specificity protein-tyrosine phosphatase vaccinia H1-related phosphatase: participation of Tyr-78 and Thr-73 residues in tuning the orientation of His-123.

Active-site cysteine strategically positioned in the P-loop of protein-tyrosine phosphatases has been suggested to be further stabilized by hydrogen bonding arrays radiating out from the P-loop to neighboring residues. In this work, we investigated the structural role of histidine array in HC(X)(5)RS motif of the vaccinia H1-related protein phosphatase (VHR), using site-directed mutagenesis in conjunction with an extensive kinetic analysis. Conserved His-123 was mutated along with neighboring residues Tyr-78 and Thr-73. The increased pK(a) values of active-site Cys-124 found in Y78F and T73A mutants (6.51 and 6.75, respectively) were comparable to those of H123A and H123F mutants. Kinetic evaluation of Y78F and T73A mutants further implicates that the mutations perturb the relative position of Cys-124 within the P-loop. These results imply that Tyr-78 and Thr-73 make up an essential part of the His-123 array and structurally tune the Cys-124 position. Tyr-78 of VHR turns out to be the invariant Tyr reported in several protein-tyrosine phosphatases by a structure-based sequence alignment. Therefore, orientation of the imidazole ring of His-123 by the invariant Tyr-78 is crucial for maintaining the proper position of Cys-124 in the P-loop.

Base Sequence↗
PubMed2006

Cloning and daily expression of the timeless gene in Aedes aegypti (Diptera:Culicidae).

Molecular approaches for studying biological rhythms in insects have been well investigated in the model Drosophila melanogaster, in which a number of genes have been characterized in terms of sequence, expression, protein interactions and involvement in the control of locomotor activity and eclosion rhythms. However, only scattered information is available for insect vectors of diseases. In this paper, we report the cloning and expression analysis of the clock gene timeless in the mosquito Aedes aegypti, vector of Dengue and Yellow Fever viruses. In Drosophila, timeless has a crucial role in the control of the central pacemaker and the resetting mechanism that allows the clock to synchronize with the environment light-dark cycles. Comparison of the predicted protein sequence encoded by timeless in Ae. aegypti and D. melanogaster demonstrated high similarity in some important domains, suggesting functional conservation. Analysis of the daily expression of timeless in Ae. aegypti shows a peak in mRNA abundance around the light-dark transition.

Activity Cycles↗
PubMed1998

A molecular analysis of hyalin--a substrate for cell adhesion in the hyaline layer of the sea urchin embryo.

The hyaline layer of echinoderm embryos is an extraembryonic matrix that functions as a substrate for cell adhesion through early development. The major constituent of the hyaline layer is the protein hyalin, a fibrillar glycoprotein of approximately 330 kDa that multimerizes in the presence of calcium. Here we provide a molecular characterization of hyalin and identify a region of the protein that is important for its function in cell adhesion. Partial hyalin cDNAs were identified from two sea urchin species, Strongylocentrotus purpuratus and Lytechinus variegatus, by screening expression libraries with monoclonal antibodies to hyalin. The cDNAs each encode a tandemly arranged series of conserved repeats averaging 84 amino acids. These hyalin repeats are as similar between the two species as they are to repeats within each species, suggesting a strong functional conservation. Analysis of this repeat shows that it is a unique sequence within the GenBank database with only weak similarity to mucoid protein sequences. The hyalin mRNA is approximately 12 kb in length and is present in developing oocytes coincident with the appearance of cortical granules, the vesicle in which the hyalin protein is specifically packaged. The mRNA is present throughout oogenesis but is rapidly lost at oocyte maturation so that eggs and early embryos have no detectable hyalin mRNA. The hyalin protein, however, remains at relatively constant levels throughout development. Thus, all the hyalin protein present during early development, when no RNA is detectable, is maternally derived and exocytosed from cortical granules at fertilization. Hyalin mRNA reaccumulates in embryos beginning at the mesenchyme blastula stage; a RNA gel blot and in situ hybridization analysis of gastrulae and larvae shows a progressive confinement of hyalin mRNA to the aboral ectoderm. Recombinant hyalin containing the tandem repeat region of the protein was expressed in bacteria and is shown to serve as an adhesive substrate, almost equal to that of native hyalin, in cell adhesion assays. This adhesive activity is partially blocked by dilute hyalin monoclonal antibody Tg-HYL to the same extent as that for native hyalin. Thus, this hyalin repeat region appears to contain the ligand for the hyalin cell surface receptor. These data help explain some of the classic functions ascribed to the hyalin protein in early development and now enable investigators to focus on the mechanisms of cell interactions with the hyaline layer.

Amino Acid Sequence↗
PubMed2000

A conserved, transcriptionally active p28 multigene locus of Ehrlichia canis.

Antigenic diversity of Ehrlichia chaffeensis and Ehrlichia canis may involve independent or differential expression of the P28 outer membrane proteins genes, enabling persistent infections of the natural hosts. In this study, we analyzed the transcriptional activity of a five gene locus in E. canis encoding homologous, but non-identical, p28 genes. The p28 multigene locus contained three previously identified complete gene sequences and one partial gene sequence. A new p28 gene was identified and sequenced, and the complete sequence of a second partial p28 gene was determined. The new p28 gene joined two previously separate loci, forming the single p28 multigene locus. The amino acid homology of the E. canis P28 proteins ranged from 51 to 74%. The nucleic acid sequence of regions compared within the locus spanning four p28 genes from two geographically distinct E. canis isolates was completely conserved. Analysis of the five p28 genes demonstrated that all were transcriptionally active in in-vitro cultures of E. canis incubated at the vertebrate host (37 degrees C) and ambient tick temperatures (27 degrees C). Polycistronic copies of multiple p28 genes were not detected by RT-PCR, but monocistronic p28 mRNA transcripts were detected by Northern blotting from E. canis infected DH82 cells, indicating that the genes are transcribed as monocistronic messages.

Amino Acid Sequence↗
PubMed2000

Hemispheric stroke following cardiac surgery: a case-control estimate of the risk resulting from ipsilateral asymptomatic carotid artery stenosis.

A case-control study was undertaken to determine if asymptomatic carotid artery stenosis (ACS) is independently associated with ipsilateral hemispheric stroke following cardiac surgery (CS). All CS patients (3069) who were at two hospitals between 1989 and 1994 were reviewed. Cases (31) selected for this study were those with hemispheric stroke within 30 days following CS. Controls (69) were taken from those without hemispheric stroke. Case-control analysis demonstrated that ACS of 50-90% and of 80-90% increased the risk of ipsilateral stroke 5.2-fold (95% confidence interval [CI] = 1.5-16.3, p = 0.01) and 24.3-fold (CI = 2.6-114.9, p = 0.002), respectively. Other variables with significant odds ratios (OR) were age > or =65 years (OR = 4.0, CI = 1.3-10.5, p = 0.01), peripheral vascular disease (OR = 3.4, CI = 1.3-8.8, p = 0.02), hypertension (OR = 3.0, CI = 1.2-7.0, p = 0.02), and female gender (OR = 3.0, CI = 1.2-7.1, p = 0.04). A second conservative analysis for missing data demonstrated a significant association for ACS of 80-90% alone (OR = 13.1, CI = 1.5-60.9, p = 0.01). This association remained significant after multivariate adjustment with propensity score stratification. ACS (80-90%) appears to be independently associated with ipsilateral hemispheric stroke following CS when evaluated against the present study variables. This finding supports the need for a properly conducted prospective natural history study, including an evaluation of aortic arch atherosclerosis, to determine the clinical relevance of this observation.

Aged↗
PubMed1999

Transcriptional analysis of the hmw gene cluster of Mycoplasma pneumoniae.

Mycoplasma pneumoniae adherence to host cells is a multifactorial process that requires the cytadhesin P1 and additional accessory proteins. The hmw gene cluster consists of the genes p30, hmw3, and hmw1, the products of which are known to be essential for cytadherence, the rpsD gene, and six open reading frames of unknown function. Putative transcriptional terminators flank this locus, raising the possibility that these genes are expressed as a single transcriptional unit. However, S1 nuclease protection and primer extension experiments identified probable transcriptional start sites upstream of the p32, p21, p50, and rpsD genes. Each was preceded at the appropriate spacing by the -10-like sequence TTAAAATT, but the -35 regions were not conserved. Analysis of the M. pneumoniae genome sequence indicated that this promoter-like sequence is found upstream of only a limited number of open reading frames, including the genes for P65 and P200, which are structurally related to HMW1 and HMW3. Promoter deletion studies demonstrated that the promoter-like region upstream of p21 was necessary for the expression of p30 and an hmw3-cat fusion in M. pneumoniae, while deletion of the promoter-like region upstream of p32 had no apparent effect. Analysis by reverse transcription-PCR confirmed transcriptional linkage of all the open reading frames in the hmw gene cluster. Taken together, these findings suggest that the genes of this locus constitute an operon expressed from overlapping transcripts.

Adhesins, Bacterial↗
PubMed2005

Congenital adrenal hyperplasia: the molecular basis of 21-hydroxylase deficiency in H-2(aw18) mice.

The mouse strain H-2(aw18) shows typical characteristics of 21-hydroxylase deficiency (21-OHD). A deletion of the active Cyp21a1 gene has been postulated; however, the changes on the nucleotide level are still unknown. To investigate whether this animal model, the only one available, is suitable for studying congenital adrenal hyperplasia in man, a detailed analysis of the Cyp21 locus has been performed to ascertain the genetic cause of 21-OHD in H-2(aw18) mice. We demonstrate that 21-OHD is caused by unequal crossing over between the active Cyp21a1 gene and the pseudogene resulting in a hybrid Cyp21a1-Cyp21a2-p gene including a partial deletion of Cyp21a1. Next to several pseudogene-specific point mutations, various novel missense mutations and a nonsense mutation are present. Enzyme activity for each point mutation has been determined in vitro and the structure-function relationship has been studied by sequence conservation analysis and a three-dimensional murine 21-hydroxylase protein (Cyp21) structure model. The mutations are classified in three classes: I, no or minor decrease in enzyme activity: R238Q, P465L, R361K, A362V, P458L; II, loss of enzyme activity caused by inefficient electron flux: R346H, R400C; III, loss of activity due to deficient substrate binding: I462F, L464F. The combination of in vitro protein expression and three-dimensional structure modeling provides a valuable tool to understand the role of the different mutations and polymorphisms on the resulting enzyme activity. The underlying genetic mechanisms are also known to be responsible for 21-OHD in humans, so rodent 21-OHD turns out to be an excellent genetic model for studying the human disease.

Adrenal Hyperplasia, Congenital↗
PubMed1992

Morphometric distinction of sclerosing adenosis from tubular carcinoma of the breast.

Objective features have been identified that assist in distinguishing sclerosing adenosis from tubular carcinoma of the breast. Hematoxylin and eosin stained paraffin sections of 18 sclerosing adenoses and 18 tubular carcinomas were studied using a TAS Plus image analysis system. Histological measurements from lumens and glands included stereologic features of architecture and morphometry of size and shape (the latter by Fourier coefficients). Cytological measurements included nuclear area, perimeter, diameter and formfactor. Initial analysis suggested utility for several individual features. However, after a modified Bonferroni procedure only two of the features were statistically significant, i.e. the coefficient of variation of luminal form factor and the surface density of glands. Multivariate discriminant analysis using these two variables correctly classified 86% of the cases, with three adenoses and two carcinomas misclassified. Validity of the discriminant rules was supported by classification using measurements from a separate, independent set of cases (ten sclerosing adenoses and nine tubular carcinomas). The classification function computed from the first set misclassified only one case from the second set, a tubular carcinoma, leaving 95% of the cases successfully categorized. Chi square test for 2 x 2 contingency tables gave a p-value < 0.001 for both sets of cases. The results suggest that morphometric features are helpful in distinguishing tubular carcinoma from sclerosing adenosis and point out the need for conservative analysis of high-dimensional data sets.

Adenocarcinoma↗
PubMed2003

SPACRCAN in the interphotoreceptor matrix of the mouse retina: molecular, developmental and promoter analysis.

SPACRCAN is a novel proteoglycan present in the interphotoreceptor matrix (IPM) of the rat and human retina that resists aqueous extraction through its binding to hyaluronan. The purpose of this study was: to clone mouse Spacrcan; to characterize the promoter elements; to define the deduced amino acid sequence; to establish the time of Spacrcan expression during retinal development; and to determine the time of appearance and distribution of SPACRCAN protein. Spacrcan cDNA clone was obtained through PCR amplification of a mouse retina cDNA library, and RT-PCR amplification and 5'RACE of mouse retina RNA. The deduced polypeptide sequence of mouse SPACRCAN contains a signal peptide at the N-terminal, seven N-link glycosylation sites, numerous potential O-linked glycosylation sites in a central mucin-like domain, two glycosaminoglycan attachment sites, five potential hyaluronan-binding motifs, two epidermal growth factor-like domains, and a hydrophobic stretch of 23 amino acids near the C-terminal. Comparison of the genomic structure of mouse and human SPACRCAN showed significant structure conservation. Analysis of the promoter region revealed several important putative regulatory elements including a Ret-1/PCE-1 element, an 11 base motif for Crx binding, six copies of PIRE, a Ret-4 element, three copies of AP-1, a CRE element, and five copies of GATA3. Northern blot analysis and immunohistochemistry were used to determine the tissue specificity of Spacrcan mRNA and to localize SPACRCAN in developing retina. Spacrcan mRNA is expressed in both retina and pineal gland and was detectable as early as embryonic day 15. The protein is first detectable in the IPM at postnatal day 8 where it increases in concert with the extension of photoreceptor inner and outer segments from the outer retinal surface. The presence of several unique regulatory elements in the promoter region and characteristic molecular features shared with the orthologue in human and rat suggest an important functional role of SPACRCAN in the IPM. The time of appearance of the SPACRCAN protein during retinal development suggests that this matrix protein may establish the extracellular microenvironment into which photoreceptor outer segments are elaborated.

Amino Acid Sequence↗