Wikipedia
Protomap may refer to:
- Protomap (neuroscience) - a hypothetical map of the ventricular zone in the brain
- Protomap (proteomics) - a proteomic technique for characterizing proteolytic events using mass spectrometry
PROTOMAP is a recently developed proteomic technology for identifying changes to proteins that manifest in altered migration by one-dimensional SDS-PAGE. It is similar, conceptually, to two-dimensional gel electrophoresis and difference gel electrophoresis in that it enables global identification of proteins that undergo altered electrophoretic migration resulting from, for example, proteolysis or post-translational modification. However, it is unique in that all proteins are sequenced using mass spectrometry which provides information on the sequence coverage detected in each isoform of each protein thereby facilitating interpretation of proteolytic events.
PROTOMAP is performed by resolving control and experimental samples in separate lanes of a 1D SDS-PAGE gel. Each lane is cut into evenly spaced bands (usually 15-30 bands) and proteins in these bands are sequenced using shotgun proteomics. Sequence information from all of these bands are bioinformatically integrated into a visual format called a peptograph which plots gel-migration in the vertical dimension (high- to low-molecular weight, top to bottom) and sequence coverage in the horizontal dimension (N- to C-terminus, left to right). A peptograph is generated for each protein the sample (thousands of peptographs are generated from a single experiment) and this data format enables rapid identification of proteins undergoing proteolytic cleavage by making evident changes in gel-migration that are accompanied by altered topography.
PROTOMAP stands for PRotein TOpography and Migration Analysis Platform and was invented and developed by Ben Cravatt and colleagues at The Scripps Research Institute.
The Protomap is a primordial molecular map of the functional areas of the mammalian cerebral cortex during early embryonic development, at a stage when neural stem cells are still the dominant cell type. The protomap is a feature of the ventricular zone, which contains the principal cortical progenitor cells, known as radial glial cells. Through a process called ' cortical patterning', the protomap is patterned by a system of signaling centers in the embryo, which provide positional information and cell fate instructions. These early genetic instructions set in motion a development and maturation process that gives rise to the mature functional areas of the cortex, for example the visual, somatosensory, and motor areas. The term protomap was coined by Pasko Rakic. The protomap hypothesis was opposed by the protocortex hypothesis, which proposes that cortical proto-areas initially have the same potential, and that regionalization in large part is controlled by external influences, such as axonal inputs from the thalamus to the cortex. However, a series of papers in the year 2000 and in 2001 provided strong evidence against the protocortex hypothesis, and the protomap hypothesis has been well accepted since then.