an introduction to GO annotations

Question

[Affan]

I have the mouse genome split into 1000 bp bins. For each bin, I'd like to know how far is it from the nearest gene. A question I posted yesterday got the answer of using biomart (and its R package biomaRt). Going through biomart, I am a bit confused about the GO ontology terms: Consider the following diagram:

Consider a particular gene, with a particular transcript:

Why would a particular protein have so many GO terms? I am a math major and never really got introduced to GO ontology so if someone could explain this to me? I understand the terms as they are defined on http://geneontology.org/page/ontology-documentation but I am not sure why a particular protein would require so many terms.

Answer 1

[Dr Reema Singh]

Hello Affan

Here's the description Go Terms -- Is It Normal To Have Multiple Go Terms Associated With A Specific Gene/Locus?

[Devon Ryan]

Good find, figures that I've answered a question like this before. In particular, the answer from justinhaselbach is useful, since it emphasizes the fact that a single gene can produce proteins with multiple functions, locations, and modes of action in different (or even the same) contexts.

Answer 2

[Pierre Lindenbaum]

As far as I can see your screen show all the ancestors of only a few GO term : e.g: cytoplasm is_part_of_a cell is_a cellular_component