DCPS (Decapping Scavenger Enzyme) Human refers to the recombinant form of the human scavenger mRNA-decapping enzyme, a critical protein in RNA metabolism. It is involved in hydrolyzing residual m7GpppN cap structures left after mRNA degradation by the exosome, ensuring complete RNA turnover . Produced in Escherichia coli, recombinant DCPS is a 40.8 kDa polypeptide chain containing 357 amino acids, fused with an N-terminal His-tag for purification .
DCPS adopts a symmetric homodimeric structure in its ligand-free state, with two distinct domains:
N-terminal domain (residues 40–145): Domain-swapped dimer critical for substrate binding .
C-terminal domain (residues 146–336): Contains the histidine triad (HIT) motif (His³³⁷–His³⁴¹–His³⁴⁵) essential for catalytic activity .
Upon binding m7GDP or m7GpppG cap analogs, DCPS transitions to an asymmetric dimer, enabling substrate hydrolysis. Structural studies reveal:
Active site closure: Induced by cap binding, facilitating phosphate release .
Hinge regions (residues 143–149): Mediate domain movement during catalysis .
DCPS hydrolyzes cap dinucleotides (e.g., m7GpppG) to m7GMP, acting downstream of 3’–5’ exosome-mediated mRNA decay . Key distinctions from Dcp2:
Feature | DCPS | Dcp2 |
---|---|---|
Substrate | Cap dinucleotides | Capped mRNA (>9 nucleotides) |
Product | m7GMP | m7GDP |
Pathway | 3’–5’ decay-coupled | 5’–3’ decay |
DCPS modulates miRNA stability independently of its decapping activity:
Cytoplasmic function: Interacts with 5’-3’ exonuclease Xrn2 to promote miRNA degradation .
Inhibition effects: DcpS knockdown or pharmacological inhibition (e.g., D156844 compound) increases miRNA levels (e.g., miR-17, miR-19b) by >2-fold in HEK293T cells .
DCPS is a validated target for SMA therapy:
Small-molecule inhibitors: Quinazoline-based compounds (e.g., D156844) bind DCPS’s closed active site, disrupting mRNA decay pathways .
Structural insights: Inhibitor binding mimics m7GpppN interaction, stabilizing asymmetric DCPS conformations .
DCPS’s role in miRNA turnover suggests broader implications in oncogenesis. Elevated miRNA levels due to DCPS inhibition alter post-transcriptional regulation of oncogenes/tumor suppressors .
Scavenger mRNA-decapping enzyme DcpS, DCS-1, Hint-related 7meGMP-directed hydrolase, Histidine triad protein member 5, HINT-5, DCPS, DCS1, HINT5, HSPC015, HSL1.
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DCPS accepts several types of research proposals, including: proposals originating within DCPS offices and departments; responses to DCPS requests for proposals for external audits and research; and unsolicited research proposals that support DCPS's strategic priorities from individuals, organizations independent of DCPS, or DCPS employees fulfilling graduate requirements. Generally, DCPS does not accept research proposals from graduate students who are not DCPS employees, with limited exceptions for former employees with good service records or those with pre-existing working relationships with DCPS .
DCPS prioritizes ethical research practices that protect students and staff. Key ethical principles include: respecting privacy and confidentiality of data as required by FERPA; minimizing interference with school instruction and operations; supporting DCPS values of equity and anti-racism; avoiding randomized control trials where students are denied services or deceived; obtaining appropriate informed consent; and ensuring all researchers pass required background checks .
DCPS recommends submitting research requests at least 90 days in advance of proposed research commencement. This timeframe allows sufficient time for both the proposal review process and the Memorandum of Agreement (MOA) process. For researchers seeking to conduct or begin research in the current school year, DCPS recommends submitting by the January submission due date at the latest. Research cannot begin until the MOA is finalized, which extends the approval process timeline .
A complete research proposal must include:
Completed template with project information
Narrative description of research methodology
Letter of support from a DCPS advocate
IRB approval or exemption documentation
All data collection instruments and protocols
Consent forms for participants or parents
The appropriate DCPS advocate depends on the research scope:
For primary data collection in one school: the school principal
For significant primary data collection in multiple schools: each principal and possibly a DCPS Chief
For secondary administrative data only: preferably a DCPS Chief, though a staff member at director level or above may sponsor if they copy their office chief
DCPS defines confidential data as:
Any student records containing Personally Identifiable Information (as defined by FERPA)
Any employment records containing individual-level data
Aggregate data constructed from student or employment records comprising groups of fewer than ten individuals
To protect confidentiality, DCPS may require that schools or the District not be identified in publications. Researchers must provide any proposed publications or presentations to DCPS for review and comment at least fourteen days prior to submission. In some instances, DCPS may require approval rights for publications or presentations, as well as co-authorship with DCPS staff. For multi-year projects, researchers must provide annual interim reports to DCPS for internal use .
Several important restrictions apply to data collection:
No DCPS staff time or resources (including email) may be used to recruit participants
School staff may not be utilized to collect data
The DCPS Central Office does not grant permission for the use of school buildings for data collection; this must be arranged with the school principal
All non-DCPS personnel participating in data collection must submit to background checks as required by law
Any research interference with school instruction and operations must be minimized
DCPS requires that research supports their values of equity and anti-racism. This means designing studies that help create environments that eliminate opportunity gaps, interrupt institutional bias, and remove barriers to academic and social success, particularly for students of color. Research methodologies should be culturally responsive and avoid perpetuating stereotypes or biases. Study designs should consider representation, inclusion, and potential differential impacts across demographic groups. Analysis plans should include examination of outcomes by relevant subgroups to identify potential equity gaps .
Research on DcpS as a therapeutic target has employed several sophisticated methodologies:
Methodology | Application | Key Findings |
---|---|---|
High-throughput screening | Cell-based reporter assay with human SMN2 gene promoter | Identified C5-quinazolines as potent inducers of SMN2 gene expression |
Protein microarray scanning | Human ProtoArray® with 5,000+ proteins probed with 125I-labeled C5-quinazoline | Identified DcpS as specific binding partner |
Biochemical assays | In vitro testing of C5-quinazolines | Confirmed potent inhibition of DcpS decapping activity |
X-ray crystallography | Co-crystallization of C5-quinazolines with DcpS | Revealed compounds trap DcpS in catalytically inactive conformation |
These methods collectively established DcpS as a novel therapeutic target for modulating gene expression by small molecules .
When analyzing contradictory data in DcpS studies, researchers should:
Compare experimental conditions carefully, as DcpS functions may differ in various cellular compartments
Consider tissue-specific effects and potential differences between in vitro and in vivo models
Examine temporal dynamics of DcpS activity and inhibition
Analyze dose-response relationships comprehensively
Consider potential compensatory mechanisms that may emerge upon DcpS inhibition
Integrate multiple experimental approaches (genetic, biochemical, structural) to resolve contradictions
Use statistical methods appropriate for the specific data types to determine significance of contradictory findings
DcpS is a nuclear shuttling protein that belongs to the histidine triad (HIT) superfamily of hydrolases. It plays a critical role in mRNA decay pathways by binding and hydrolyzing the m7GpppN mRNA cap structure. Specifically, DcpS functions in the 3′-5′ exonucleolytic pathway to hydrolyze the residual cap structure (m7GpppN) to m7GMP + pN after the mRNA body has been degraded. It also has functions in the 5′-3′ pathway. As a modulator of RNA metabolism, DcpS represents a novel therapeutic target for conditions where altering gene expression could provide benefit .
C5-quinazolines act as potent inhibitors of DcpS through a unique mechanism:
They bind directly to the DcpS enzyme
This binding traps the DcpS dimer in an open, catalytically incompetent conformation
Specifically, one monomer of the enzyme is "closed" by binding the inhibitor, while the other monomer is held in an "open" conformation
This structural change prevents DcpS from performing its normal enzymatic function of hydrolyzing the m7GpppN cap structure
The potency of inhibition correlates with potency for SMN2 promoter induction, suggesting a direct mechanistic link
The connection between DcpS inhibition and SMA treatment involves several key mechanisms:
SMA is caused by deletion or mutation of both copies of the SMN1 gene that produces the essential SMN protein
Disease severity is modified by variable copy numbers of a second gene, SMN2, which produces incorrectly spliced mRNA
C5-quinazoline compounds that inhibit DcpS have been shown to increase SMN2 gene expression by approximately two-fold
This increased expression of SMN2 can potentially compensate for the loss of SMN1, providing therapeutic benefit
The molecular pathway linking DcpS inhibition to SMN2 upregulation appears to involve changes in RNA metabolism, though the precise mechanism requires further elucidation
When designing experimental controls for DcpS inhibitor studies, researchers should implement:
Vehicle controls matching the solvent used for inhibitor delivery
Dose-response experiments to establish concentration-dependent effects
Structurally similar but inactive compounds to control for non-specific effects
Genetic controls (siRNA/CRISPR knockdown of DcpS) to compare with pharmacological inhibition
Time course experiments to distinguish immediate versus delayed effects
Cell type controls to determine tissue specificity of responses
Positive controls with known DcpS inhibitors for reference
Rescue experiments with DcpS overexpression to confirm specificity
When analyzing human subject data from DCPS studies, researchers should:
Use appropriate statistical methods based on study design (e.g., t-tests, ANOVA, regression analysis, multilevel modeling)
Account for clustering effects in school-based data using hierarchical linear models
Consider potential selection bias and implement proper statistical controls
Ensure adequate sample sizes for statistical power, particularly for subgroup analyses
Address missing data appropriately using methods like multiple imputation
Control for relevant covariates including demographic and school-level factors
Use both statistical significance and effect size measures to interpret findings
Consider adjustment for multiple comparisons when conducting numerous tests
Translating DcpS findings from molecular studies to clinical applications requires:
Validation in multiple model systems of increasing complexity (cells → tissues → animal models → human samples)
Pharmacokinetic/pharmacodynamic studies to determine if inhibitors reach target tissues at effective concentrations
Biomarker development to monitor target engagement and therapeutic response
Safety studies to identify potential off-target effects and toxicities
Determination of appropriate dosing regimens based on molecular mechanisms
Identification of patient populations most likely to benefit from DcpS-targeted therapies
Development of combination approaches with other therapeutic strategies
Design of clinically relevant outcome measures that reflect the molecular mechanisms of action
Emerging areas of DcpS research beyond SMA include:
Exploration of DcpS roles in other neurological disorders where RNA metabolism may be dysregulated
Investigation of DcpS function in cancer biology, as RNA processing is frequently altered in malignancies
Studies of DcpS in cellular stress responses and potential applications in stress-related disorders
Examination of DcpS in aging processes and age-related diseases
Development of novel DcpS modulators with improved pharmacological properties
Investigation of tissue-specific functions of DcpS that might enable targeted therapeutic approaches
Exploration of DcpS interactions with other RNA processing pathways and potential synergistic therapeutic targets
DCPS prioritizes research that advances their strategic goals, including:
Promoting equity and anti-racism in educational settings
Eliminating opportunity gaps and removing barriers to academic success
Interrupting institutional bias in educational practices
Improving outcomes for students of color and other underserved populations
Developing evidence-based interventions that support DCPS's mission to make it "the best urban school district in the country"
Creating favorable conditions for high-quality research while respecting instructional time and individual privacy
Building partnerships with the research community to benefit students and staff and contribute to wider improvement of public education
Advanced RNA sequencing technologies will likely impact DcpS research by:
Providing more comprehensive views of transcriptome-wide effects of DcpS inhibition
Enabling single-cell analysis to detect cell type-specific responses to DcpS modulation
Allowing detailed examination of alternative splicing patterns influenced by DcpS activity
Facilitating investigation of non-coding RNA interactions with DcpS
Enabling precise quantification of mRNA decay rates following DcpS inhibition
Supporting identification of direct RNA targets of DcpS through techniques like CLIP-seq
Improving detection of rare transcript variants that may be particularly sensitive to DcpS modulation
Enhancing understanding of the regulatory networks connected to DcpS function
To obtain IRB approval for DCPS human subjects research:
Determine which IRB has jurisdiction (typically your institution's IRB)
Prepare a comprehensive protocol describing research questions, methodology, participant selection, risks/benefits, and data security measures
Develop appropriate consent/assent forms following IRB and DCPS guidelines
Submit all materials to your institutional IRB for review
Address any IRB concerns or requested modifications
Obtain formal IRB approval or exemption documentation
Include the IRB approval or exemption documentation with your DCPS research proposal
Note that DCPS approval is separate from and additional to IRB approval - both are required
When recruiting DCPS students and staff:
Clearly describe who is to be recruited and how recruitment will take place
Remember that no DCPS staff time or resources (including email) may be used for recruitment
School staff may not be utilized to collect data
Arrange use of school buildings for data collection directly with the school principal after proposal approval
Understand that participation is at the discretion of principals
Ensure all non-DCPS personnel participating in data collection submit to required background checks
Minimize disruption to school operations and instructional time
Follow all approved protocols for obtaining informed consent/assent
When compensating DCPS research participants:
Follow DCPS Policy on Compensation for Participation in Research Studies
Ensure compensation is appropriate and not coercive
Consider non-monetary forms of recognition or compensation where appropriate
Clearly describe any compensation in research proposals and consent forms
Follow relevant tax and reporting requirements for monetary compensation
Maintain records of all compensation provided to participants
Ensure equity in compensation practices across participant groups
Obtain approval for the compensation plan as part of the research proposal review process
Resources available to researchers include:
Detailed guidelines in the "DCPS Process and Requirements to Conduct Research or Obtain Confidential Data" document
The DCPS organizational chart to help identify appropriate advocates
Direct contact with the Office of Data Systems & Strategy via researchrequests@k12.dc.gov
The online proposal submission form at https://forms.office.com/r/sS4SASnYQU
Access to a SharePoint folder for uploading proposal materials after form submission
Appendices in the guidelines document providing templates and additional information
DCPS staff who may serve as advocates for research projects
Information about DCPS strategic priorities to align research proposals
For specialized equipment needs in DcpS molecular studies, researchers should:
Establish collaborations with facilities that have protein crystallography capabilities for structural studies
Seek access to high-throughput screening platforms for identifying novel DcpS modulators
Partner with institutions that have protein microarray technology for target identification
Utilize core facilities with advanced mass spectrometry for protein-ligand interaction analysis
Access molecular modeling resources for computational drug design approaches
Collaborate with laboratories equipped for RNA sequencing and analysis
Connect with centers having animal facilities for in vivo testing of DcpS inhibitors
Consider shared resource facilities at academic institutions or research consortia
Research networks for DcpS and related enzymes include:
Academic research consortia studying RNA metabolism and processing
SMA research networks investigating various therapeutic approaches
Structural biology collaborations focusing on enzyme mechanisms
Drug discovery partnerships between academia and industry
Patient advocacy organizations supporting SMA and related research
Rare disease research networks with interest in RNA-targeted therapeutics
Computational biology groups working on RNA regulatory networks
Translational research centers bridging basic science and clinical applications
When encountering conflicting data in DcpS inhibition studies:
Verify compound purity and identity using analytical techniques (NMR, mass spectrometry)
Confirm target engagement using multiple orthogonal assays
Test for off-target effects using selectivity panels
Examine cell type-specific responses that might explain different outcomes
Consider the influence of experimental conditions (timing, dosage, etc.)
Validate key findings using alternative methodological approaches
Assess reproducibility across different laboratory settings
Integrate findings through comprehensive meta-analysis of available data
Common pitfalls in DCPS human subjects research include:
Insufficient planning for recruitment challenges - address by building flexible timelines and multiple recruitment strategies
Inadequate attention to DCPS equity requirements - ensure research design explicitly supports equity goals
Incomplete documentation in proposals - use the provided checklist to verify all required elements
Underestimating time for approvals - submit at least 90 days before planned start date
Missing required DCPS advocate support - identify and engage advocates early in proposal development
Designing overly burdensome data collection - minimize disruption to school operations
Inadequate data security measures - develop comprehensive data protection protocols
Insufficient consideration of student well-being - prioritize student needs above research goals
When encountering unexpected findings in DcpS functional studies:
Verify the results through independent repetition of experiments
Consider whether technical issues might explain the unexpected outcome
Explore whether the finding reveals a previously unknown function of DcpS
Design targeted follow-up experiments to systematically investigate the phenomenon
Review literature for similar observations that might provide context
Consider consulting with experts in related fields for alternative perspectives
Evaluate whether the finding opens new research directions worth pursuing
Document thoroughly, even if the finding contradicts initial hypotheses, as it may lead to important discoveries
The Decapping Enzyme, Scavenger (DCPS) is a crucial component in the mRNA decay pathway. This enzyme plays a significant role in the final step of the 3’ end mRNA decay process, ensuring the proper degradation of mRNA molecules. The human recombinant form of this enzyme is produced using advanced biotechnological methods, typically involving expression in E. coli.
The human recombinant DCPS is used extensively in research to study mRNA decay mechanisms. It is also employed in various biochemical assays to understand the role of mRNA decapping in gene expression regulation. The enzyme’s ability to hydrolyze cap structures makes it a valuable tool in molecular biology and genetic research .
For short-term storage, the enzyme can be kept at 4°C. For long-term storage, it is recommended to store the enzyme at -20°C. To prevent degradation, it is advisable to avoid multiple freeze-thaw cycles. Adding a carrier protein, such as 0.1% HSA or BSA, can further enhance the enzyme’s stability during storage .