Ubiquitin-Like Modifier Proteins Flashcards
what is a PTM?
a covalent attachment of particular modifier to a protein after the translation of its mRNA, this process is usually enzymatic
what are PTMs required for?
regulation and control of protein-protein-interactions
what are PPIs?
physical contacts between two or more proteins as result of non-covalent interactions
transient/long term
strong/weak
what is ubiquitination?
a covalent PTM of most proteins and dictates protein fate
what is the function of mono and poly-Ubs?
PPIs
protein localisation
protein activity modulation
what is the function of poly-Ubs?
target proteins to 26s proteosome
target proteins to lysosome for repairs
cytokine signalling
what are two techniques for studying ubiquitination?
expression of vectors and site-directed mutagenesis
what is M1 (MET) ubiquitination?
created by linear chains of Ub linked to iniator MET
what is the E3 ligase responsible for M1 ubiquitination?
linear Ub chain assembly complex (LUBAC)
what is SUMO?
a small ubiquitin related modifier which undergoes sumoylation
has different isoforms nad there are different consensus binding sites
what is sumo signalling?
function to facilitate PPIs, but sumoylation also implicated in almost all nuclear cell process
how does sumo facilitate PPIs?
via sumo interacting motif (SIM)
what is SUMO/Ub crosstalk?
sumo targeted ubiquitin ligase (STUbL)
implicated in acute promyelocytic leukemia (APL)
