protein-protein interactions/ relationship.pptx

protein protein interactions

1. “PROTEIN-PROTEIN INTERACTIONS” PRESENTED TO: Dr. Sumaira Rasool PRESENTED BY: Ambreen Mehvish

2. INTRODUCTION Proteins are the workhorses that facilitate most biological processes in a cell. Protein–protein interactions  occur when two or more proteins bind together, often to carry out their biological function. These interactions are very important in our lives,can lead to fatal diseases such as Alzheimer’s disease.

3. The protein –protein interaction have commonly been termed as the ‘INTERACTOME’ by scientists. French researchers first coined the term " interactome " in 1999; the first protein-protein interactome data appeared in 2000. Today the field—like the 16-years-old... Interactome research has racked up more than 600 publications, and databases now house interactions numbering in thousands.

4. WHY IS STUDY OF INTERACTOME IMPORTANT? Proteins, like humans, are social animals. The work of the cell is accomplished mostly by macromolecular complexes Unlike biological pathways, which represent a sequence of molecular interactions leading to a final result — for example, a signalling cascade — networks are interlinked.

5. Represented as starbursts of protein 'nodes' linked by interaction 'edges' to form intricate constellations . Furthermore, placing proteins encoded by disease genes into these networks will let researchers determine the best candidates for assessing disease risk and therapies. Therefore, finding interaction partners for a protein can reveal its function.

6. The human genome project effort identified 30,000 genes, but that is not the end goal. How the genes work in pathways ?? To accomplish this it is necessary to systematically map gene and protein interactions. The interactome may be tougher to solve than the genome, but the information, is crucial for a complete understanding of biology.

7. CATEGORIES OF PPI STABLE: These comprise of interactions that last for a long duration. E.g.: Haemoglobin TRANSIENT: these are on/off temporary. Interactions that last a short period of time. E.g.: Muscle Contraction

8. METHODS FOR DETECTING PPI Main approaches for detecting interacting proteins: IN VIVO METHOD : Yeast two hybrid system IN VITRO METHOD : Immunoprecipitation ( ip )/ co- ip IN SILICO METHOD: Computational system

9. YEAST TWO HYBRID SYSTEM The most frequently used binary method is the yeast two-hybrid (Y2H) system . The strategy interrogates two proteins, called bait and prey, coupled to two halves of a transcription factor and expressed in yeast. If the proteins make contact, they reconstitute a transcription factor that activates a reporter gene.

10. CO-IMMUNOPRECIPITATION ( coIP ) Co- immunoprecipitation (co-IP) is a popular technique for protein interaction discovery. Co-IP is conducted in essentially the same manner as an  immunoprecipitation (IP)  of a single protein. Target protein precipitated by the antibody, called "bait", is used to co-precipitate a binding partner/protein complex, or "prey".

11. DATABASES Primary databases that contain protein–protein interactions include DIP ( http://dip.doe-mbi.ucla.edu ), BioGRID ( Biological General Repository for Interaction Datasets ) IntAct ( http://www.ebi.ac.uk/intact ) MINT ( http://mint.bio.uniroma2.it ). STRING ( Search Tool for the Retrieval of Interacting Genes/Proteins) HAPPI ( Human annotated and predicted protein interactions )

12. STRING ( Search Tool for the Retrieval of Interacting Genes/Proteins ) STRING  is a database of known and predicted  protein–protein interactions . The STRING database contains information from numerous sources, including experimental data, computational prediction methods and public text collections. The latest version 10.0 contains information on about 9.6 million proteins from more than 2000 organisms.   The resource also serves to highlight functional enrichments in user-provided lists of proteins, using a number of functional classification systems such as GO,  Pfam and KEGG.

13. STRING imports protein association knowledge from databases of physical interaction and databases of curated biological pathway knowledge… (MINT, HPRD, BIND,  DIP,BioGRID , KEGG,  Reactome ,  IntAct , NCI-Nature Pathway Interaction Database, GO).

14.   Proteins that have a similar function or an occurrence in the same metabolic pathway, must be expressed together and have similar  phylogenetic profile .

15. CONCLUSION The predictve power of the interactome model allows us to examine the organization and coordination of multiple complex cellular processes and determine how they are organized into pathways. The interactome model can be used to predict poorly characterized proteins into their functional context according to their interacting partners within a module. One-to-many relationship can be used for pathway discovery.

16. THANKS!!!!