Abstract
The development of tourism can be considered from a tourist and a local perspective. The tourism space functions both as a tourism destination and a living space for local residents. Methods ...of atmospheric design can contribute to consider the guest’s view which can bring dynamism into the development of places and locations. This is seen as an interesting option for the Bavarian small town of Eichstaett in Germany, whose challenges and opportunities in tourism development are the focus of this contribution. Small towns have the potential to achieve tourism visibility and to increase the quality of life of the local population through a stronger engagement with the atmospheric design of their space.
Summary
Stimulus‐specific calcium (Ca
2+
) signals have crucial functions in developmental processes in many organisms, and are deciphered by various Ca
2+
‐binding proteins. In
Arabidopsis thaliana
..., a signaling network consisting of calcineurin B‐like (
CBL
) protein calcium sensors and
CBL
‐interacting protein kinases (
CIPK
s) has been shown to fulfil pivotal functions at the plasma membrane in regulating ion fluxes and abiotic stress responses. However, the role of tonoplast‐localized
CBL
proteins and especially their function in regulating developmental programs remains largely unknown. In this study, we analyzed single and double mutants of the closely related tonoplast‐localized calcium sensors
CBL
2 and
CBL
3, which show either reduction of function (rf) or complete loss of function (lf). While single
cbl2
or
cbl3
mutants did not display discernable phenotypes,
cbl2
/
cbl3
mutants exhibited defects in vegetative growth and were severely impaired in seed development and morphology. Seeds of the
cbl2
/
3rf
mutant were smaller in size and exhibited reduced weight and fatty acid content compared to wild‐type, but accumulation of sucrose was not altered. Moreover, accumulation of inositol hexakisphosphate (InsP
6
), the major storage form of phosphorus in seeds, was significantly reduced in mutant seeds. In addition, complete loss of
CBL
2 and
CBL
3 function in
cbl2
/
3lf
resulted in a high frequency of severe defects in embryonic development. Together, our findings reveal a crucial function of Ca
2+
‐controlled processes at the vacuolar membrane as determinants of seed yield and size, and demonstrate the importance of vacuolar
CBL
calcium sensors for plant embryogenesis.
Capping protein (CP), also known as CapZ in muscle cells and Cap32/34 in Dictyostelium discoideum, plays a major role in regulating actin filament dynamics. CP is a ubiquitously expressed heterodimer ...comprising an α- and β-subunit. It tightly binds to the fast growing end of actin filaments, thereby functioning as a "cap" by blocking the addition and loss of actin subunits. Vertebrates contain two somatic variants of CP, one being primarily found at the cell periphery of non-muscle tissues while the other is mainly localized at the Z-discs of skeletal muscles.
To elucidate structural and functional differences between cytoplasmic and sarcomercic CP variants, we have solved the atomic structure of Cap32/34 (32=β- and 34=α-subunit) from the cellular slime mold Dictyostelium at 2.2 Å resolution and compared it to that of chicken muscle CapZ. The two homologs display a similar overall arrangement including the attached α-subunit C-terminus (α-tentacle) and the flexible β-tentacle. Nevertheless, the structures exhibit marked differences suggesting considerable structural flexibility within the α-subunit. In the α-subunit we observed a bending motion of the β-sheet region located opposite to the position of the C-terminal β-tentacle towards the antiparallel helices that interconnect the heterodimer. Recently, a two domain twisting attributed mainly to the β-subunit has been reported. At the hinge of these two domains Cap32/34 contains an elongated and highly flexible loop, which has been reported to be important for the interaction of cytoplasmic CP with actin and might contribute to the more dynamic actin-binding of cytoplasmic compared to sarcomeric CP (CapZ).
The structure of Cap32/34 from Dictyostelium discoideum allowed a detailed analysis and comparison between the cytoplasmic and sarcomeric variants of CP. Significant structural flexibility could particularly be found within the α-subunit, a loop region in the β-subunit, and the surface of the α-globule where the amino acid differences between the cytoplasmic and sarcomeric mammalian CP are located. Hence, the crystal structure of Cap32/34 raises the possibility of different binding behaviours of the CP variants toward the barbed end of actin filaments, a feature, which might have arisen from adaptation to different environments.
Transient and stable expression of transgenes is central to many investigations in plant biology research. Chemical regulation of expression can circumvent problems of plant lethality caused by ...constitutive overexpression or allow inducible knock （out/down） approaches. Several chemically inducible or repressible systems have been described and successfully applied. However, cloning and application-specific modification of most available inducible expression systems have been limited and remained complicated due to restricted cloning options. Here we describe a new set of 57 vectors that enable transgene expression in transiently or stably transformed cells. All vectors harbor a synthetically optimized XVE expression cassette, allowing I~-estradiol mediated protein expression. Plasmids are equipped with the reporter genes GUS, GFP, mCherry, or with HA and Strepll epitope tags and harbor an optimized multiple cloning site for flexible and simple clon- ing strategies. Moreover, the vector design allows simple substitution of the driving promoter to achieve tissue-specificity or to modulate expression ranges of inducible transgene expression. We report details of the kinetics and dose-dependence of expression induction in Arabidopsis leaf mesophyll protoplasts, transiently transformed Nicotiana benthamiana leaves, and stably transformed Arabidopsis plants. Using these vectors, we investigated the influence of CBL （Calcineurin B-like） protein expression on the subcellular localization of CIPKs （Calcineurin B-like interacting protein kinases）. These analyses uncovered that induced co-expression of CBL3 is fully sufficient for dynamic translocation of CIPK5 from the cytoplasm to the tonoplast. Thus, the vector system presented here facilitates a broad range of research applications.
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