: J Biol Chem. 2004 Mar 11 [Epub ahead of print] Links    Broad-spectrum Identification of cellular SUMO substrate proteins. Zhao Y, Kwon SW, Anselmo A, Kaur K, White MA. Cell Biology, UT Southwestern medical Center, Dallas, TX 75390. Reversible covalent modification of proteins with SUMO (small ubiquitin-related modifier) is emerging as an important system contributing to dynamic regulation of protein function. To enhance our understanding of the cell regulatory systems impacted by sumoylation, we are using affinity chromatography coupled HPLC/MS/MS for unbiased identification of candidate cellular SUMO substrate proteins. Here we describe the identification of 21 candidate sumoylated proteins from whole-cell lysates of HEK293 cells. The nature of the proteins identified is consistent with a role for sumoylation in diverse cell regulatory systems, but highlights regulation of chromatin organization and gene expression as major systems targeted by the sumoylation machinery. PMID: 15016812 [PubMed - as supplied by publisher] ----------------------------------------------------------------------------------------------- TABLE 1. SUMO targets Identified proteins MW [kDa]# of peptides ID NCBI # Sumoylation machinery RanBP2 * 357.9 6 NP_006258 SUMO-1 E1 C subunit 71.2 5 AAD12784 SUMO-1 E1 N subunit 38.4 8 NP_005491 Sumo E2I 20.4 5 AAH00744 Sumo 2 14.7 10 XP_212611 Sumo 1 11.5 16 NP_003343 Chromatin Associated Factors PML* 90.6 2 NP_150242 TIF1-beta 88.5 2 NP_005753 TFII-I 110 4 NP_127494 NXP-2 108.2 1 Q14149 zinc finger protein 262 136.2 2 NP_005086 Dna Topoisomerase I * 66.6 2 1LPQ_A BTB-like domain proteins similar to MGC25497 83.4 1 NP_945342 MGC2628 26.5 3 NP_076981 RNA Polymerases RNA Pol III subunit 155kD 155.6 3 NP_008986 RNA Pol III subunit RPC2 127.6 3 NP_060552 RNA Pol III subunit RPC5 77.4 2 BAA95976 RNA Pol III subunit 62kD 60.6 2 NP_006459 RNA Pol III RPC8 19.6 1 AAH17248 RNA Pol I subunit 38.6 1 NP_004866 RNA Pol II subunit RPB5 24.5 1 AAC03238 Other RanGAP1* 67.3 8 BAB47464 HSP70.1 70 4 P08107 ERp72 72.9 4 NP_004902 ErbB3 147.8 1 NP_001973 polymyositis/scleroderma autoantigen 2 100.7 1 XP_001527 NOP5 52.4 2 AAF29084 * indicates previously indentified SUMO target. TABLE 2. Consensus SUMO Target Sites Identified proteins (A,V,L,I,F,W,M) K X E TIF1-beta VKEE, IKEE TFII-I VKTE, VKEE, VKEE, IKQE NXP-2 IKAE, MKSE, VKKE, VKKE, VKAE, IKTE zinc finger protein 262 AKEE, AKSE similar to MGC25497 VKSE, IKQE MGC2628 None RNA Pol III subunit 155kD AKAE, AKYE RNA Pol III subunit RPC2 None RNA Pol III subunit RPC5 AKLE, IKEE RNA Pol III subunit 62kD None RNA Pol III RPC8 None RNA Pol I subunit None RNA Pol II subunit RPB5 None HSP70.1 None ERp72 VKEE, FKGE, VKFE ErbB3 IKRE polymyositis/scleroderma autoantigen 2 AKSE, IKSE NOP5 AKLE, AKTE, VKVE, IKEE