News | Fernando Moreno Herrero Lab

Functional characterization of the different oligomeric forms of human surfactant protein SP-D

Surfactant Protein D (SP-D) is a collectin protein that participates in the innate immune defense of the lungs. SP-D mediates the clearance of invading microorganisms by opsonization, aggregation or direct killing, which are lately removed by macrophages.
SP-D is found as a mixture of trimers, hexamers, dodecamers and higher order oligomers, “fuzzy balls”. However, it is unknown whether there are differences between these oligomeric forms in functions, activity or potency.

Structure and activity of human surfactant protein D from different natural sources

Surfactant protein D (SP-D) is a C-type lectin that participates in the innate immune defense of lungs. It binds pathogens through its carbohydrate recognition domain in a calcium-dependent manner. Human surfactant protein D (hSP-D) has been routinely obtained from bronchoalveolar lavage of patients suffering from pulmonary alveolar proteinosis (PAP) and from amniotic fluid (AF). As a consequence of the disease, hSP-D obtained from PAP is found in higher amounts and is mainly composed of higher order oligomeric forms

January 2020

January (2020). New paper published in Nucleic Acids Research on the Dynamics of DNA Nicking and Undwinding by the RepC-PcrA complex

January (2020). Alejandro participates on the event “Science in the classroom” by giving a guided tour of the CNB facilities and an introduction of our research work to high school students from the IES ¨Ciudad de los Ángeles¨.

Sequence-dependent mechanical properties of double-stranded RNA

The mechanical properties of double-stranded RNA (dsRNA) are involved in many of its biological functions and are relevant for future nanotechnology applications. DsRNA must tightly bend to fit inside viral capsids or deform upon the interaction with proteins that regulate gene silencing or the immune response against viral attacks. However, the question of how the nucleotide sequence affects the global mechanical properties of dsRNA has so far remained largely unexplored. Here, we have employed stateof-the-art atomistic molecular dynamics simulations to unveil the mechanical response of different RNA duplexes to an external force

SEBBM 2019

Fernando Moreno-Herrero together with Eduardo Oliver (CNIC), were responsible for the organization of “The 42nd Congress of the Spanish Biochemical and Molecular Biology Society”, that was held in Madrid on 16-19th July 2019, and count on the presence and support of the Minister of science, Innovation and Universities Pedro Duque during the Opening Ceremony.

ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements

Bacillus subtilis ParB forms multimeric networks involving non-specific DNA binding leading to DNA condensation. Previously, we found that an excess of the free C-terminal domain (CTD) of ParB impeded DNA condensation or promoted decondensation of pre-assembled networks (Fisher et al., 2017). However, interpretation of the molecular basis for this phenomenon was complicated by our inability to uncouple protein binding from DNA condensation.

Bacillus subtilis MutS modulates RecA-mediated DNA strand exchange between divergent DNA sequences

Natural transformation contributes to acquisition and spread of antibiotic resistance and pathogenicity traits.We show that Bacillus subtilis chromosomal transformation decreased logarithmically with increased sequence divergence up to 15% in wild type (wt) cells or in cells lacking MutS2 or mismatch repair proteins (MutL, MutS or both).

February 2019

February (2019). We welcome Mikel Marín Baquero to the lab, to carry out his PhD in AFM and fluorescence.

February (2019). New paper published in Physical Review Letters on the DNA Crookedness Regulates DNA Mechanical Properties at Short Length Scales.

February (2019). Nature Reviews Physics Highlight our on DNA crookedness and its relation with stretching flexibility. LINK

February (2019). Fernando attends the Spanish Mechano-Biology Network Meeting in Zaragoza and gives a talk.

February (2019). Clara, Silvia, Carolina y Alejandro participate on 11 Feb events:

International Day of Woman and Girls Science.

Clara, Silvia and Carolina carries out some experiments with milk and colorants here in the CNB.

Clara talks about unrolling DNA at the IES Severo Ochoa.

Alejandro talks about four famous female scientics and performs experiments to young students at the the social and cultural center La Casa Encendida in the center of Madrid.

February (2019) New paper published in Frontiers in Microbiology on the Bacillus subtilis MutS and RecA-Mediated DNA Strand Exchange.

February (2019) C. Carrasco gives a talk at the Mechanobiology Seminars at CNIC, Madrid.

February (2019). Julene Madriaga defends her PhD Thesis: Magnetic Tweezers and Fluorescence to study DNA – protein interactions.

DNA crookedness regulates DNA mechanical properties at short length scales

Sequence-dependent DNA conformation and flexibility play a fundamental role in the specificity of DNA-protein interactions. Here we quantify the DNA crookedness: a sequence-dependent deformation of DNA that consists of periodic bends of the base pair centers chain.

Human CtIP forms a tetrameric dumbbell-shaped particle which binds and bridges complex DNA end structures for double-strand break repair