An extract on #artsagram
Following are some major signaling pathways, demonstrating how ligands binding to their receptors can affect second messengers and eventually result in altered cellular responses.
MAPK/ERK pathway: A pathway that couples intracellular responses to the binding of growth factors to cell surface receptors. This pathway is very complex and includes many protein components. In many cell types, activation of this pathway promotes cell division, and many forms of cancer are associated with aberrations in it.
cAMP-dependent pathway: In humans, cAMP works by activating protein kinase A (PKA, cAMP-dependent protein kinase) (see picture), and, thus, further effects depend mainly on cAMP-dependent protein kinase, which vary based on the type of cell.
IP3/DAG pathway: PLC cleaves the phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2) yielding diacyl glycerol (DAG) and inositol 1,4,5-triphosphate (IP3). DAG remains bound to the membrane, and IP3 is released as a soluble structure into the cytosol. IP3 then diffuses through the cytosol to bind to IP3 receptors, particular calcium channels in the endoplasmic reticulum (ER). These channels are specific to calcium and allow the passage of only calcium to move through. This causes the cytosolic concentration of Calcium to increase, causing a cascade of intracellular changes and activity. In addition, calcium and DAG together works to activate PKC, which goes on to phosphorylate other molecules, leading to altered cellular activity. End-effects include taste, manic depression, tumor promotion, etc.
The area north of the Highway #1 from the South Central Peninsula is called the North End; both areas being predominantly urban residential older housing which is undergoing gentrification. Much of the North End is made up of the former city of Portland and comprises another former working class area which is slowly undergoing gentrification at the eastern end of Douglas Avenue; immediately north of Portland and upstream from the Reversing Falls is the former community of Indiantown.
Vessels navigating the Saint John River can only transit the Reversing Falls gorge at slack tide, thus Indiantown became a location during the 19th and 20th centuries where tugboats and paddle wheelers could dock to wait. Being located at the beginning of the navigable part of the Saint John River, Indiantown also became a major terminal for vessels departing to ply their trade upriver.
Further north of the central part of the city, and northeast of the North End and Portland, along the southern bank of the Kennebecasis River is the area of Millidgeville which is generally considered a neighbourhood separate from the North End. The boundary of Millidgeville is typically thought to begin at the "Y" intersection of Somerset Street and Millidge Ave or right after Tartan St. It is a middle to upper-class neighbourhood. Located here is University of New Brunswick, as well as New Brunswick's largest health care centre, the Saint John Regional Hospital, and Saint John's only completely French school and community centre, Centre Scolaire Communautaire Samuel-de-Champlain.
The eastern area of the North End plays host to the city's largest park, and one of Canada's largest urban parks. Rockwood Park encompasses 890 hectares of upland Acadian mixed forest, many hills and several caves, as well as several freshwater lakes, with an extensive trail network, a golf course, and the Cherry Brook Zoo. The park was designed by Calvert Vaux in the mid-to-late 19th century. Mount Pleasant borders the park, and is generally seen as distinct from the traditionally poorer North End.