The Eukaryotic Linear Motif resource for
Functional Sites in Proteins
Accession:
Functional site class:
Taspase1 cleavage site
Functional site description:
Taspase1 is a threonine aspartase which was first identified as the trithorax (MLL) family processing enzyme.
ELM Description:
MLL (alias HRX), a SET domain histone methyltransferase involved in epigenetic gene regulation, is cleaved at two sites (Hsieh,2003; Yokoyama,2002) by a threonine aspartase termed Taspase1 (Hsieh,2003). Cleavage is between the conserved Asp-Gly in the motif. The resulting N- and C-terminal fragments (p320 and p180) associate to form a stable heterodimer which localises to the nucleus (Hsieh,2003). In the absence of Taspase1 (by RNAi), MLL is not cleaved and HOX gene expression becomes deregulated (Hsieh,2003). It was recently pointed out that the MLL cleavage sites are virtually identical to a conserved cleavage site in the general transcription factor TFIIA (the alfa/beta precursor) (Hoiby,2004). Although it has not been shown that Taspase1 cleaves TFIIA, the regular expression for this motif takes this possibility into account.
Pattern: Q[MLVI]DG..[DE]
Pattern Probability: 0.0000048
Present in taxon: Eukaryota
Interaction Domain:
Asparaginase_2 (PF01112) Asparaginase (Stochiometry: 1 : 1)
o See 2 Instances for CLV_TASPASE1
o Abstract
MLL (alias HRX), a SET domain histone methyltransferase involved in epigenetic gene regulation, is cleaved at two sites (Hsieh,2003; Yokoyama,2002) by a threonine aspartase termed Taspase1 (Hsieh,2003). Cleavage is between the conserved Asp-Gly in the motif. The resulting N- and C-terminal fragments (p320 and p180) associate to form a stable heterodimer which localises to the nucleus (Hsieh,2003). In the absence of Taspase1 (by RNAi), MLL is not cleaved and HOX gene expression becomes deregulated (Hsieh,2003). It was recently pointed out that the MLL cleavage sites are virtually identical to a conserved cleavage site in the general transcription factor TFIIA (the alfa/beta precursor) (Hoiby,2004). Although it has not been shown that Taspase1 cleaves TFIIA, the regular expression for this motif takes this possibility into account.
o 4 selected references:

o 2 GO-Terms:

o 2 Instances for CLV_TASPASE1
(click table headers for sorting; Notes column: =Number of Switches, =Number of Interactions)
Acc., Gene-, NameStartEndSubsequenceLogic#Ev.OrganismNotes
Q03164 MLL
MLL1_HUMAN
2664 2670 KRSAEGQVDGADDLSTSDED TP 2 Homo sapiens (Human)
Q03164 MLL
MLL1_HUMAN
2716 2722 DLPKISQLDGVDDGTESDTS TP 2 Homo sapiens (Human)
Please cite: ELM 2016-data update and new functionality of the eukaryotic linear motif resource. (PMID:26615199)

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