Rabbit FKBP59-heat shock protein binding immunophillin (HBI) is a calmodulin binding protein.

FKBP59-HBI, a heat shock protein hsp90-binding immunophilin that was originally detected in heterooligomer forms of steroid receptors, is retained on Calmodulin (CAM)-Sepharose 4B in the presence of 2 mM Ca2+ and is eluted by EGTA, demonstrating a specific p59-CAM interaction. The p59 amino acid sequence reveals the presence of two putative CAM binding sites in a helix regions of the protein, as well as PEST sequences which are generally present in CAM-binding proteins. In vitro proteolysis by calpain II (a Ca(2+)-activated neutral protease), another feature of CAM-binding proteins, generates shorter peptides revealed by the mAb EC1, but not by the pAb 173 which recognizes the C-terminal of the protein. The potential function of CAM binding by the hsp90-binding immunophilin is discussed.     

Human neutrophil cytosolic phospholipase C: partial characterization.

The activity of neutrophil cytosolic phospholipase C on PIP2 and PI was compared employing [3H]inositol-labeled heat-inactivated membranes of differentiated HL-60 cells, into which tracer [32P]PIP2 was incorporated. Hydrolysis of PIP2 did not require Ca2+ and was stimulated when the content of PIP2 in the membrane was increased by incorporation of unlabeled inositol lipid. At equal concentrations of PI and PIP2 in the membrane, hydrolysis of PIP2 was faster and no evidence of competition between the two substrates was obtained. Incorporation of PI into PE-[32P]PIP2 vesicles, accelerated PIP2 hydrolysis also at conditions that favor hydrolysis of PI. Partial purification of neutrophil cytosolic PLC on Q Sepharose, phenyl Sepharose and heparin-Agarose columns is described. From heparin-Agarose column, two PLC activity peaks exhibiting different substrate specificities were eluted. The elution profile of the main PLC species from Superose 12 gel filtration column was compatible with an approx. 150 kDa protein.     

Evolutionary analysis of the multigene pregnancy-specific β1-Glycoprotein family: Separation of historical and nonhistorical signals

The pregnancy-specific ₁-glycoproteins (PSG) form a large family of closely related proteins. Using newly developed methods of sequence analysis, in combination with protein modeling, we provide a framework for investigating the evolution and biological function of genes like the PSG. Evolutionary trees, based on C-terminal sequence, group PSG genes in a manner consistent with their genomic organization. Trees constructed using the N-terminal domain sequences are unreliable as an indicator of phylogeny because of non-neutral processes of sequence change. During duplication of the PSG genes, evolutionary pressures have resulted in a gradient of constrained change across each gene. The N-terminal domains show a nonrandom pattern of amino acid substitutions clustered in the immunoglobulin complementarity-determining region (CDR)-like regions, which appear to be important in the function of the protein.     

Calcified structures and calcification in protists

Summary The diversity of calcified structures found in protists, the mechanisms utilized to form these structures, and the role these structures play in the taxonomy and systematics of the protists are presented. The two most frequently studied orders of protists which produce calcified structures, the coccolithophorids and foraminifera, are featured. However, consideration is given to the less known and least studied organisms.     

The Surface Exclusion System of RP1: Investigation of the Roles of trbJ and trbK in the Surface Exclusion, Transfer, and Slow-Growth Phenotypes

The contiguous trbJ and trbK genes of RP1 were cloned individually to study their effects. Surface exclusion was conferred only by trbK and only when gene dosage was high or when trbJ was also present in cis or in trans. This suggests that in the low-copy-number RP1, surface exclusion is due to a two-gene interaction in which trbK is the dominant partner. Among surface exclusion genes, trbJ is novel in yielding a periplasmic product that is also essential for conjugal transfer. This cellular location and the disturbed membrane function that accompanies TrbJ-processing probably accounts for the retarded growth caused by trbJ⁺ clones in Pseudomonas aeruginosa strain PAO.     

Genetics and biochemistry of phenol degradation byPseudomonas sp. CF600

Pseudomonas sp. strain CF600 is an efficient degrader of phenol and methylsubstituted phenols. These compounds are degraded by the set of enzymes encoded by the plasmid locateddmpoperon. The sequences of all the fifteen structural genes required to encode the nine enzymes of the catabolic pathway have been determined and the corresponding proteins have been purified. In this review the interplay between the genetic analysis and biochemical characterisation of the catabolic pathway is emphasised. The first step in the pathway, the conversion of phenol to catechol, is catalysed by a novel multicomponent phenol hydroxylase. Here we summarise similarities of this enzyme with other multicomponent oxygenases, particularly methane monooxygenase (EC 1.14.13.25). The other enzymes encoded by the operon are those of the well-knownmeta-cleavage pathway for catechol, and include the recently discoveredmeta-pathway enzyme aldehyde dehydrogenase (acylating) (EC 1.2.1.10). The known properties of thesemeta-pathway enzymes, and isofunctional enzymes from other aromatic degraders, are summarised. Analysis of the sequences of the pathway proteins, many of which are unique to themeta-pathway, suggests new approaches to the study of these generally little-characterised enzymes. Furthermore, biochemical studies of some of these enzymes suggest that physical associations betweenmeta-pathway enzymes play an important role. In addition to the pathway enzymes, the specific regulator of phenol catabolism, DmpR, and its relationship to the XylR regulator of toluene and xylene catabolism is discussed.     

ANNUAL DIFFERENCES IN FEMALE REPRODUCTIVE SUCCESS AFFECT SPATIAL AND COHORT-SPECIFIC GENOTYPIC HETEROGENEITY IN PAINTED TURTLES

Long-term ecological data were used to evaluate the relative importance of movements, breeding structure, and reproductive ecological factors to the degree of spatial and age-specific variation in genetic characteristics of painted turtles (Chrysemys picta) on the E. S. George Reserve in southeastern Michigan. Estimates of the degree of spatial genetic structuring were based on the proportion of total genotypic variance partitioned within and between subpopulations (inferred from hierarchical F-statistics based on variation at 18 protein loci), and in terms of gene correlations (co-ancestry among individuals derived from reproductive data on full-sib families of females nesting at specific nesting areas). Little variation in allele frequency was observed among turtles from different marshes (F_mt = 0.003), though significant variation was observed among turtles from different nesting areas associated with each marsh (F_nm = 0.046). Gene correlations among individuals within nesting areas varied greatly over years (0.032-0.171; mean = 0.069) and were negatively correlated to the proportion of females that successfully nested during each year. General concordance between independent estimates of genotypic correlations (i.e., F_nm derived from protein electrophoretic variation vs. mean co-ancestry) suggests that allozyme data, when collected over spatial scales consistent with species behavioral characteristics and reproductive ecology, may accurately reflect the apportionment of gene diversity within and among subpopulations. The magnitude and patterning of allelic variation among nesting areas and individuals appears to be primarily a function of gametic correlations among members of full-sib families, irrespective of the degree of gene flow or female nesting-site fidelity. Comparisons of genetic characteristics among 11 cohorts (1974-1984) revealed that heterozygosity (H) and inbreeding coefficients (F) varied greatly. Cohort estimates of H and F were correlated to female nesting success and to estimates of co-ancestry for the same years. Results clearly reflect the concomitant importance of ecological factors (principally the proportion of the female population that successfully produce offspring during each year) in determining the magnitude and patterning of gene correlations within and among groups, and to the genotypic composition of offspring born during each year.     

Relationships of reproductive traits and body size with attainment of sexual maturity and age in Blanding's turtles (Emydoidea blandingi)

To place associations among body size, age at maturity, age, and reproductive traits of a long-lived organism in the context of current life history models based on the concept of norms of reaction, we examined data from a mark-recapture study of Blanding's turtles (Emydoidea blandingi) in southeastern Michigan during 24 of the years between 1953 and 1988. Females matured between 14 and 20 years of age. Both the smallest and largest adult females in the population were reproducing for the first time in their lives. This result suggests that a combination of differences in juvenile growth rates and ages at maturity, and not indeterminate growth, are the primary cause of variation in body size among adults. Body size variation among individuals was not related to age at sexual maturity. Females that had slower growth rates as juveniles matured later at similar mean body size compared to those with more rapid growth that matured at an earlier age. As a result, a linear model of age at sexual maturity with growth rates of primiparous females between hatching and maturity was significant and negative (R² = 0.76). Frequency of reproduction of the largest and smallest females was not significantly different. Clutch size did not vary significantly with age among either primiparous or multiparous females. Clutch sizes of primiparous females and multiparous females were not significantly different. However, older females (>55 years minimum age) reproduced more frequently than did younger females (minimum age <36 y).     

Low species turnover of upland Amazonian birds in the absence of physical barriers

Aim

One of the oldest and most powerful ways for ecologists to explain distinct biological communities is to invoke underlying environmental differences. But in hyper-diverse systems, which often display high species richness and low species abundance, these sorts of community comparisons are especially challenging. The classic view for Amazonian birds posits that riverine barriers and habitat specialization determine local and regional community composition. We test the tacit, complementary assumption that similar bird communities should therefore permeate uniform habitat between major rivers, regardless of distance.

Location

Upland (terra firme) rainforests of central Amazonia.

Methods

We conducted intensive whole-community surveys of birds in three pairs of 100-ha plots, separated by 40–60 km. We then used dissimilarity indices, cluster analysis, and ordination to characterize differences among the six avian communities.

Results

In all, we detected 244 forest-dependent birds, with an average of 190 species (78%) per plot. Species turnover was negligible, no unique indicator species were found among plot pairs, and all documented species were already known from a complete inventory at one of the three sites.

Main Conclusions

Our study corroborates the classic biogeographical pattern and suggests that turnover contributes little to regional avian diversity within upland forests. Using a grain size of 100 ha, this implies that upland birds perceive the environment as uniform, at least over distances of ~60 km. Therefore, to maximize both local species richness and population persistence, our findings support the conservation of very large tracts of upland rainforest. Our analyses also revealed that the avifauna at Reserva Ducke, encroached by urban sprawl from the city of Manaus, shows the hallmarks of a disturbed community, with fewer vulnerable insectivores. This defaunation signals that even an enormous preserve (10 × 10 km) in lowland Amazonia is not insulated from anthropogenic degradation within the surrounding landscape.