Family income buffers the relationship between childhood adverse experiences and putamen volume

Adverse experiences and family income in childhood have been associated with altered brain development. While there is a large body of research examining these associations, it has primarily used cross-sectional data sources and studied adverse experiences and family income in isolation. However, it is possible that low family income and adverse experiences represent dissociable and potentially interacting profiles of risk. To address this gap in the literature, we examined brain structure as a function of adverse experiences in childhood and family income in 158 youths with up to five waves of MRI data. Specifically, we assessed the interactive effect of these two risk factors on six regions of interest: hippocampus, putamen, amygdala, nucleus accumbens, caudate, and thalamus. Adverse experiences and family income interacted to predict putamen volume (B = 0.086, p = 0.011) but only in participants with family income one standard deviation below the mean (slope estimate = −0.11, p = 0.03). These results suggest that adverse experiences in childhood result in distinct patterns of brain development across the socioeconomic gradient. Given previous findings implicating the role of the putamen in psychopathology-related behaviors, these results emphasize the importance of considering life events and socioeconomic context when evaluating markers of risk. Future research should include interactive effects of environmental exposures and family income to better characterize risk for psychopathology in diverse samples.     

Rapid measurement of <Superscript>3</Superscript>J(H<Superscript>N</Superscript>–H<Superscript>α</Superscript>) and <Superscript>3</Superscript>J(N–H<Superscript>β</Superscript>) coupling constants in polypeptides

We present two NMR experiments, (3,2)D HNHA and (3,2)D HNHB, for rapid and accurate measurement of 3J(H N-H alpha) and 3J(N-H beta) coupling constants in polypeptides based on the principle of G-matrix Fourier transform NMR spectroscopy and quantitative J-correlation. These experiments, which facilitate fast acquisition of three-dimensional data with high spectral/digital resolution and chemical shift dispersion, will provide renewed opportunities to utilize them for sequence specific resonance assignments, estimation/characterization of secondary structure with/without prior knowledge of resonance assignments, stereospecific assignment of prochiral groups and 3D structure determination, refinement and validation. Taken together, these experiments have a wide range of applications from structural genomics projects to studying structure and folding in polypeptides.     

Solution Structure and Calcium-Binding Properties of M-Crystallin, A Primordial βγ-Crystallin from Archaea

The lens βγ-crystallin superfamily has many diverse but topologically related members belonging to various taxa. Based on structural topology, these proteins are considered to be evolutionarily related to lens crystallins, suggesting their origin from a common ancestor. Proteins with βγ-crystallin domains, although found in some eukaryotes and eubacteria, have not yet been reported in archaea. Sequence searches in the genome of the archaebacterium Methanosarcina acetivorans revealed the presence of a protein annotated as a βγ-crystallin family protein, named M-crystallin. Solution structure of this protein indicates a typical βγ-crystallin fold with a paired Greek-key motif. Among the known structures of βγ-crystallin members, M-crystallin was found to be structurally similar to the vertebrate lens βγ-crystallins. The Ca^2 +-binding properties of this primordial protein are somewhat more similar to those of vertebrate βγ-crystallins than to those of bacterial homologues. These observations, taken together, suggest that amphibian and vertebrate βγ-crystallin domains are evolutionarily more related to archaeal homologues than to bacterial homologues. Additionally, identification of a βγ-crystallin homologue in archaea allows us to demonstrate the presence of this domain in all the three domains of life.     

Isolation of recombinant plasmids containing structural gene sequences for rat seminal vesicle secretory proteins IV and V

Double stranded cDNA was made to partially purified mRNA for the small seminal vesicle secretory proteins IV and V. This ds cDNA was then inserted into the Pst 1 site of pBR322 by the (G-C) homopolymer tailing technique. Bacterial transformants harboring plasmids with specific inserts were identified by translation of mRNA that was hybridized to plasmid DNA immobilized on nitrocellulose. Separate plasmids were obtained with cDNA inserts for both SVS IV and V. Neither hybridization results nor preliminary restriction analysis gave any indication for homology between them.     

Backbone 1H, 13C and 15N resonance assignments of an intrinsically unstructured βγ-crystallin from Hahella chejuensis

The sequence specific backbone ¹H, ¹³C and ¹⁵N resonance assignments of an intrinsically unstructured βγ-crystallin from Hahella chejuensis are reported. The secondary structure chracterization of the unstructured protein reveals that large fraction of residues exhibits β-strand propensity, as in the case of the Ca²⁺-bound structured protein.     

Homopurine and homopyrimidine strands complementary in parallel orientation form an antiparallel duplex at neutral pH with A-C,G-T,and T-C mismatched base pairs

DNA sequences d-TGAGGAAAGAAGGT (a 14-mer) and d-CTCCTTTCTTCC (a 12-mer) are complementary in parallel orientation forming either Donahue (reverse Watson-Crick) base pairing at neutral pH or Hoogsteen base pairing at slightly acidic pH. The structure of the complex formed by dissolving the two strands in equimolar ratio in water has been investigated by nmr. At neutral pH, the system forms an ordered antiparallel duplex with five A : T and four G : C Watson-Crick base pairs and three mismatches, namely G-T, A-C, and T-C. The nuclear Overhauser effect cross-peak pattern suggests an overall B-DNA conformation with major structural perturbations near the mismatches. The duplex has a low melting point and dissociates directly into single strands with a broad melting profile. The hydrogen-bonding schemes in the mismatched base pairs have been investigated. It has been shown earlier that in acidic pH, the system prefers a triple-stranded structure with two pyrimidine strands and one purine strand. One of the pyrimidine strands has protonated cytosines, forms Hoogsteen base pairing, and is aligned parallel to the purine strand; the other has nonprotonated cytosines and has base-pairing scheme similar to the one discussed in this paper. The parallel duplex is therefore less stable than either the antiparallel duplex or the triplex, in spite of its perfect complementarity. © 1997 John Wiley & Sons, Inc. Biopoly 41: 773–784, 1997     

Isolation of the gene for the testis-specific H1 histone variant H1t

H1t is a testis-specific H1 variant found in pachytene spermatocytes and round spermatids of mammals. The H1t gene was isolated from the Sargent-Bonner library of recombinant lambda bacteriophage containing EcoRI fragments of rat liver DNA using a hybridization probe derived from a chicken H1 variant. The rat H1t gene encodes a 207-amino acid protein (ignoring the initiating methionine) that matches perfectly what is known of the sequence and composition of H1t isolated from rat testes. The gene lacks introns and has good matches to all the consensus sequences known to lie upstream from a variety of H1 genes from diverse organisms. It also has the standard downstream palindromic sequence that specifies the 3'-end of most histone messages. Accordingly, the features of the gene or its environs that restrict its expression to a particular phase of spermatogenesis are not yet evident.