Proteins
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Translation of messenger RNA (mRNA) occurs on the ribosome. Folding of the nascent polypeptide begins, assisted by chaperones.
The polypeptide proceeds to post-translational folding. The new protein is correctly folded into its tertiary structure.
Some proteins are translocated into organelles, such as mitochondria. Unfolded and misfolded polypeptides aggrgate and precipitate in an inclusion body.
Unfolded or partially folded polypeptides are freed from the aggregates by chaperones and refolded or degraded in the proteasome.
Functional classification
ligand binding protein or carrier proteins
nucleic-acid binding proteins
- transcription factors
enzymes
transporter proteins (tranport proteins)
storage proteins
structural proteins
signal transducer proteins
motor proteins
unknown or not assigned
According to the localization
membrane proteins
coat proteins
cytosolic proteins
organelles proteins
nuclear proteins
Features
protein synthesis
vesicle-mediated sorting of proteins
intracellular transport of proteins
protein mutations
protein folding and protein misfolding
protein transport (protein trafficking)
protein sorting
protein function
protein localization
protein carbonylation
protein farnsesylation
protein phosphorylations
protein domains
Protein pathology (Proteins citated in www.humpath.com)
by genic mutation (proteins mutated in human diseases) (In july 2004, 1,484 human genes implicated in human diseases have been listed in Online Mendelian Inheritance in Man - OMIM)
by fixation of an antibody
by fixation of a microbial toxin
by interaction with viral proteins
by chemical inactivation
protein surexpression
- gene amplification in tumors
- translocation downstream an activated promoter
fusion proteins in tumors
inactivation by mutations
- haploinsufficiency
- recessive loss of function mutations
activation by mutations
- resistance to degradation
- creation of new functions
For one protein
splice variant products
post-translational modifications,
subcellular localizations
assembly into vomplexes
protein-protein interactions
Videos
Protein synthesis
Protein structure
References
Chung JJ, Shikano S, Hanyu Y, Li M. Functional diversity of protein C-termini: more than zipcoding? Trends Cell Biol. 2002 Mar;12(3):146-50. PMID: 11859027
Yewdell JW. Not such a dismal science: the economics of protein synthesis, folding, degradation and antigen processing. Trends Cell Biol. 2001 Jul;11(7):294-7. PMID: 11413040
Frand AR, Cuozzo JW, Kaiser CA. Pathways for protein disulphide bond formation. Trends Cell Biol. 2000 May;10(5):203-10. PMID: 10754564
Elementary courses
BMB 211: ELEMENTARY BIOCHEMISTRY > Peptides and Proteins at Penn Sate
P.S.
PROW, Protein Reviews on the Web InterPro at EMBL-EBI tigr protein families SwissProt PFAM, Protein families database of alignments and HMMs Preotein Explorer Rasmol SCOP, Structural Classification of Proteins at the WEHI, Melbourne, Australia The Human Protein Reference Database at Johns Hopkins Laboratory