metaRLK

Receptor-like kinases (RLKs) are the most important protein kinases in plants that sense environmental signals, similar to how G protein-coupled receptors (GPCRs) function in animals. Throughout the plant life cycle, RLKs play pivotal roles in the regulation of diverse biological processes, including growth, development, and response to stress stimuli, helping plants adapt to challenging habitats. The RLK family composes Receptor Kinases (RKs) and Receptor-like Cytoplasmic Kinases (RLCKs). A typical RK in plant is structured with an extracellular domain (ECD), a hydrophobic transmembrane domain (TM), and a cytoplasmic kinase domain (KD). The ECD perceives external stimuli, and the signal is transduced along the TM region, activating the cytoplasmic KD to phosphorylate substrate. This event can induce protein complex formation or position proteins correctly.

Since the discovery of the first RLK in 1990, research on RLKs has primarily focused on specific RLKs and RLCKs. While a limited number of RLKs in model plants have been annotated, functional clues are even scarcer for non-model plants. Herein, we have established the metaRLK database, offering a comprehensive characterization and cataloging of RLKs from 528 plant genomes across seven plant groups. We have formulated a coherent gene nomenclature (PENGUIN) and a topology classification that elucidates the topology distinctions between RK and RLCK, including the presence or absence of ECDs and the presence and location of Leucine-Rich Repeats (LRR). Furthermore, metaRLK provides a valuable framework for annotating data from RLK experimental assays, elucidating RLK functions and regulation. The database also incorporates search tools using Gene ID, Species ID, Gene Name, and Uniprot ID, facilitating researchers in locating RLKs relevant to their research interests.

RLK classification and statistic

Shiu Type (RK) RLCK-TM  RLCK  RK  RK-IDE 
C-LEC 48 18 737 16
CR4L 734 2696 1212 1698
CrRLK1L-1 958 4208 11314 81
DLSV 8051 24399 53612 443
DSLV 8 99 12 1
Extensin 1587 467 4531 44
L-LEC 1481 3099 20726 368
LRK10L-2 3314 4098 6893 3820
LRR-I-1 1257 2301 9859 369
LRR-II 852 944 8665 347
LRR-III 2072 2351 23545 678
LRR-IV 100 116 1917 60
LRR-IX 150 223 3873 151
LRR-V 343 459 6294 218
LRR-VI-1 103 167 4156 113
LRR-VI-2 676 247 3686 962
LRR-VII-1 74 69 2873 89
LRR-VII-2 49 73 1436 32
LRR-VII-3 24 40 1073 48
LRR-VIII-1 287 478 6463 318
LRR-Xa 228 326 2659 104
LRR-Xb-1 925 346 5931 191
LRR-Xb-2 20 14 721 14
LRR-XI-1 1756 2752 30308 1153
LRR-XI-2 904 122 624 58
LRR-XII-1 1907 3010 20781 568
LRR-XIIIa 809 222 2039 70
LRR-XIIIb 132 119 1797 42
LRR-XIV 55 204 1774 46
LRR-XV 64 32 1673 108
LysM 796 1899 3957 1832
PERK-1 1557 1485 221 4564
RKF3 135 99 2138 24
SD-2b 2227 2009 19167 972
Singleton 6 29 490 10
URK-1 225 400 989 9
URK-2 349 140 192 509
URK-3 23 10 260 126
URK-Pp-1 40 28 339 5
URK-Pp-2 4 0 35 0
WAK 2736 5046 13895 754
WAK_LRK10L-1 957 949 4698 2369
Shiu Type (RLCK) RLCK-TM  RLCK  RK  RK-IDE 
LRR-I-2 2179 197 6 9
PERK-2 248 4472 9 15
Pp 11 8 0 0
RLCK-II 25 1153 0 3
RLCK-IV 811 2140 30 360
RLCK-IXa 2069 254 36 207
RLCK-IXb 301 13309 60 35
RLCK-Os 1221 630 33 18
RLCK-Pp 57 17 7 6
RLCK-V 6856 776 35 63
RLCK-VI 404 9898 39 39
RLCK-VIIa-1 288 10271 25 14
RLCK-VIIa-2 1203 25203 85 52
RLCK-VIIb 29 960 3 2
RLCK-VIII 159 5986 26 6
RLCK-X 1871 181 8 121
RLCK-XI 1729 122 7 5
RLCK-XII-1 100 6443 4 4
RLCK-XII-2 61 1834 18 0
RLCK-XIII 422 768 2 5
RLCK-XV 107 2163 17 41
RLCK-XVI 1439 83 20 124
RLCK-XVII 10 115 1 0

Species