EYFP Fused to Human Growth Hormone Factor 1 (Pit1)
EYFP is an enhanced yellow fluorescent variant of Aequorea victoria GFP. Though considered poor attributes for some applications, EYFP's sensitivities to chloride ions and acidic pH levels have been exploited advantageously by some researchers to develop new biosensors. The cells appearing in the digital image above were resident in a culture labeled with EYFP fused to growth hormone factor 1 (Pit1). Pit1 is a transcription factor specific to the mammalian pituitary gland. Research indicates that Pit 1 plays an important role in the regulation of a number of genes and the expression of various hormones, such as the glucocorticoids.