The proteome of human retina

Abstract

The retina is a delicate tissue that detects light, converts photochemical energy into neural signals, and transmits the signals to the visual cortex of the brain. A detailed protein inventory of the proteome of the normal human eye may provide a foundation for new investigations into both the physiology of the retina and the pathophysiology of retinal diseases. To provide an inventory, proteins were extracted from five retinas of normal eyes and fractionated using SDS-PAGE. After in-gel digestion, peptides were analyzed in duplicate using LC-MS/MS on an Orbitrap Elite mass spectrometer. A total of 3436 nonredundant proteins were identified in the human retina, including 20 unambiguous protein isoforms, of which eight have not previously been demonstrated to exist at the protein level. The proteins identified in the retina included most of the enzymes involved in the visual cycle and retinoid metabolism. One hundred and fifty-eight proteins that have been associated with age-related macular degeneration were identified in the retina. The MS proteome database of the human retina may serve as a valuable resource for future investigations of retinal biology and disease. All MS data have been deposited in the ProteomeXchange with identifier PXD001242 (http://proteomecentral.proteomexchange.org/dataset/PXD001242).

Keywords: Age-related macular degeneration; Biomedicine; Eye; Human; Phototransduction; Retina.

Figure 1

Pie diagram of the distribution of protein functions using PANTHER.

Figure 2. Kinome of the human retina, shown by spectral count/mass (kDa)

Mitogen-activated protein kinase 1 (MAPK1); protein kinase C alpha type (PRKCA) and beta type (PRKCB); dual specificity mitogen-activated protein kinase 1 (MAPK1), 2 (MAPK2), and 4 (MAPK4); tyrosine protein kinase LYN (LYN) and BAZ1B (BAZ1B); serine/threonine protein kinase DCLK1 (DCLK1), DCLK2 (DCLK2), mTOR (MTOR), P4P4 homolog (PRP4B), 25 (STK25), OSR1 (OXSR1), MRCK alpha (CDC42BPA), and MRCK beta (CDC42BPB); mitogen-activated protein kinase 4 (MAPK4) and 9 (MAPK9); Rho-associated protein kinase (ROCK1); AP2-associated protein kinase (AAK1); SRSF protein kinase (SRPK2); inactive tyrosine protein kinase 8 (PTK7); testis-specific serine/threonine protein kinase 4 (TSSK4); calcium/calmodulin-dependent protein kinase type IV (CAMK4); integrin-linked protein kinase (ILK); serine protein kinase ATM (ATM).