**2. Receptor Like Kinases (RLKs)**

### **2.1 Proteins with extracellular N-terminal LRR domains, a TM domain and an intracellular STYKc (tyrosine kinase catalytic) domain which is close to the Cterminus**

These proteins are expected to play roles in intercellular communication during tissue identity maintenance and regulation of development. Still some of them have been shown to play a role in innate immunity. Interaction with the extracellular LRR domains results in activation of the intracellular STYK catalytic domain. Then, the activated receptor, in response, catalyses the phosphorylation of tyrosine residues in intracellular proteins.

NP\_191196;AT3G56370; Leucine rich repeat transmembrane protein kinase. (Inflorescence and root apices receptor-like kinase (IRK). (Hattan et al., 2004)

NP\_195809;AT5G01890; Leucine rich repeat transmembrane protein kinase

NP\_180864;AT2G33050; Receptor Like Protein 26; protein binding . Notice loss of carboxyl

NP\_173167;AT1G17240; Receptor Like Protein 2; protein binding

NP\_173168;AT1G17250; Receptor Like Protein 3; protein binding

and root apices receptor-like kinase (IRK). (Hattan et al., 2004)

NP\_195809;AT5G01890; Leucine rich repeat transmembrane protein kinase

**2.1 Proteins with extracellular N-terminal LRR domains, a TM domain and an intracellular STYKc (tyrosine kinase catalytic) domain which is close to the C-**

response, catalyses the phosphorylation of tyrosine residues in intracellular proteins.

NP\_191196;AT3G56370; Leucine rich repeat transmembrane protein kinase. (Inflorescence

These proteins are expected to play roles in intercellular communication during tissue identity maintenance and regulation of development. Still some of them have been shown to play a role in innate immunity. Interaction with the extracellular LRR domains results in activation of the intracellular STYK catalytic domain. Then, the activated receptor, in

**2. Receptor Like Kinases (RLKs)** 

terminal TM.

**terminus** 

(GASSSHO 2). (GASSHO 1 and 2 show 76% AA homology. They are required for the formation of normal epidermal surface during embryogenesis (Tsuwamoto et al., 2008).

NP\_201371;AT5G65700; Leucine rich repeat transmembrane protein kinase. (BAM1/ Barely any meristem 1). Bam receptors regulate stem cell specification and organ development through interactions with Clavata signaling (DeYoung & Clark,2008).

NP\_190536;AT3G49670; Leucine rich repeat transmembrane protein kinase. (Bam2)

NP\_193760;AT4G20270; Leucine rich repeat transmembrane protein kinase (Bam3). BAM 1,2 and 3 exhibit 49% AA identity). Notice the presence of a second TM at the amino terminus of Bam 3 which evolution diluted for Bam 1 and 2.

The LRR and TM Containing Multi-Domain Proteins in Arabidopsis 85

NP\_178330;AT2G02220; ATP binding / protein kinase (Phytosulfokine (PSK) Receptor 1).PSK may play a role in pathogen or herbivore interactions (Loivamaki et al.,(2010)

(NP\_188604 and NP\_178330 exhibit 29.3% AA identity.)

NP\_196311;AT5G06940; Leucine rich repeat family protein

NP\_190342; AT3G47580; Leucine rich repeat transmembrane protein kinase

NP\_190293; AT3G47090; Leucine rich repeat transmembrane protein kinase

NP\_566892; AT3G47570; Leucine rich repeat transmembrane protein kinase

NP\_190295; AT3G47110; Leucine rich repeat transmembrane protein kinase

bacterial PAMP EF – Tu. (Zipfel, et al., 2006).

NP\_197548; AT5G20480; ATP binding / protein kinase (EF-TU receptor) It recognizes

three HAESA proteins function in developmentally regulated floral organ abscision (Jinn et al., 2000). (NP\_174166, NP\_194578 and NP\_201372 exhibit 37% AA identity.)

NP\_188604;AT3G19700; ATP binding / protein kinase (Haiku 2) Haiku 2 may play a role in the determination of seed size by endosperm (Garcia et al.,2003).

NP\_180875;AT2G33170; Leucine rich repeat transmembrane protein kinase

NP\_174166;AT1G28440; ATP binding/protein serine/threonine kinase (HAESA-Like1)

NP\_194578;AT4G28490; ATP binding/protein serine/threonine kinase (HAESA)

al., 2000). (NP\_174166, NP\_194578 and NP\_201372 exhibit 37% AA identity.)

NP-199777;AT5G49660; Leucine rich repeat transmembrane protein kinase

NP\_188604;AT3G19700; ATP binding / protein kinase (Haiku 2) Haiku 2 may play a role in

NP\_197965;AT5G25930; Leucine rich repeat family protein kinase

the determination of seed size by endosperm (Garcia et al.,2003).

NP\_201372;AT5G65710; ATP binding /protein serine/threonine kinase (HAESA-Like2) The three HAESA proteins function in developmentally regulated floral organ abscision (Jinn et

NP\_178330;AT2G02220; ATP binding / protein kinase (Phytosulfokine (PSK) Receptor 1).PSK may play a role in pathogen or herbivore interactions (Loivamaki et al.,(2010) (NP\_188604 and NP\_178330 exhibit 29.3% AA identity.)

NP\_197548; AT5G20480; ATP binding / protein kinase (EF-TU receptor) It recognizes bacterial PAMP EF – Tu. (Zipfel, et al., 2006).

The LRR and TM Containing Multi-Domain Proteins in Arabidopsis 87

NP\_178330;AT2G02220; Phytosulfokine receptor (PSK R1) ATP binding / protein serinethreonine kinase. (PSK represents a class of hormones that affects cellular longevity and

NP\_200200;AT5G53890; Leucine-rich repeat transmembrane protein kinase

NP\_181713;AT2G41820: Leucine-rich repeat transmembrane protein kinase

NP\_174702;AT1G34420; Leucine rich repeat transmembrane protein kinase

NP\_177694;AT1G75640; Leucine rich repeat transmembrane protein kinase

NP\_193826;AT4G20940, Leucine rich repeat transmembrane protein kinase

molecules are not listed here.

Note: For molecules such as NP\_172468 SMART does not recognize any LRR regions. Hence, these

growth ( Matsubayashi et al., 2006).

NP\_199445;AT5G46330; ATP binding / protein kinase (Flagellin sensitive 2 (FLS) .It recognizes bacterial flagellin and evokes plant innate immunity (Lu, et al., 2010)

NP\_180150;AT2G25790: Leucine rich repeat / transmembrane protein kinase

 NP\_178304;AT2G01950; BRI1-like2 ATP binding / protein serine-threonine kinase. This kinase interacts with vascular-specific adaptor proteins to influence leaf venation. (Ceserani et al.,2009.) Note absence of amino terminal TM.

NP\_187946;AT3G13380; BRI1-like3 ATP binding / protein serine-threonine kinase. Note absence of amino terminal TM.

NP\_195650;AT4G39400; Brassinosteroid insensitive 1 (BRI1) ATP binding / protein serinethreonine kinase. (Brassinosteroids regulate plant development by way of a signal transduction pathway involving BRI1 and BAK1 transmembrane receptor kinases (Wang et al., 2008).

NP\_175957;AT1G55610; BRI1-like1 ATP binding / protein serine threonine kinase.

NP\_196345;AT5G07280; EMS1 (Excess Microsporocytes 1) Transmembrane receptor protein kinase. (This protein controls somatic and reproductive cell fates in the anther of Arabidopsis.) (Zhao et al., 2002) Note absence of the amino terminal TM.

NP\_199445;AT5G46330; ATP binding / protein kinase (Flagellin sensitive 2 (FLS) .It recognizes bacterial flagellin and evokes plant innate immunity (Lu, et al., 2010)

NP\_180150;AT2G25790: Leucine rich repeat / transmembrane protein kinase

et al.,2009.) Note absence of amino terminal TM.

absence of amino terminal TM.

al., 2008).

 NP\_178304;AT2G01950; BRI1-like2 ATP binding / protein serine-threonine kinase. This kinase interacts with vascular-specific adaptor proteins to influence leaf venation. (Ceserani

NP\_187946;AT3G13380; BRI1-like3 ATP binding / protein serine-threonine kinase. Note

NP\_195650;AT4G39400; Brassinosteroid insensitive 1 (BRI1) ATP binding / protein serine-

transduction pathway involving BRI1 and BAK1 transmembrane receptor kinases (Wang et

NP\_196345;AT5G07280; EMS1 (Excess Microsporocytes 1) Transmembrane receptor protein

threonine kinase. (Brassinosteroids regulate plant development by way of a signal

NP\_175957;AT1G55610; BRI1-like1 ATP binding / protein serine threonine kinase.

kinase. (This protein controls somatic and reproductive cell fates in the anther of

Arabidopsis.) (Zhao et al., 2002) Note absence of the amino terminal TM.

NP\_178330;AT2G02220; Phytosulfokine receptor (PSK R1) ATP binding / protein serinethreonine kinase. (PSK represents a class of hormones that affects cellular longevity and growth ( Matsubayashi et al., 2006).

NP\_200200;AT5G53890; Leucine-rich repeat transmembrane protein kinase

NP\_181713;AT2G41820: Leucine-rich repeat transmembrane protein kinase

NP\_174702;AT1G34420; Leucine rich repeat transmembrane protein kinase

NP\_177694;AT1G75640; Leucine rich repeat transmembrane protein kinase

NP\_193826;AT4G20940, Leucine rich repeat transmembrane protein kinase

Note: For molecules such as NP\_172468 SMART does not recognize any LRR regions. Hence, these molecules are not listed here.

The LRR and TM Containing Multi-Domain Proteins in Arabidopsis 89

NP\_201198; AT5G63930; Leucine rich repeat transmembrane protein kinase

NP\_174809:AT1G35710; Leucine rich repeat transmembrane protein kinase

NP\_192625, AT4G08850; Leucine rich repeat transmembrane protein kinase

NP\_176483;AT1G62950; Leucine rich repeat transmembrane protein kinase

NP\_565084;AT1G74360; Leucine rich repeat transmembrane protein kinase

NP\_190742;AT3G51740; Inflorescence Meristem Receptor-Like Kinase (IMK2)

"perceives "phytosulfokines (Amano et al., 2007)).

NP\_177374;AT1G72300; Leucine rich repeat transmembrane protein kinase, (This protein

(Fisher &Turner,2007)

NP\_200956;AT5G61480; Leucine rich repeat transmembrane protein kinase..PXY receptor. (This receptor like-kinase is essential for polarity during plant vascular tissue development.

### **2.2 The members below possess a TM domain at the amino terminus and a second one in front of the STYKc domain:**

NP\_201029;AT5G62230; Erecta – like 1 (ERL1); kinase. Mediates morphological alterations. (Uchida et al.;2011).

NP\_196335;AT5G07180; Erecta – like 2 (ERL 2); kinase

NP\_173217;AT1G17750;Leucine rich repeat / transmembrane protein kinase. PEP receptor 2 (PEPR2). The amino terminal TM islost (overly mutated).

NP\_177451; AT1G73080; ATP binding / protein serine/ threonine kinase, PEP1 receptor (PEPR1). (PEP1and 2 are implicated in Arabidopsis development and immunity) ( Postel , et al.;2010). (PEPR1 and PEPR2, both perceive the existence of an endogenous danger signal Peptide 1 when such a peptide is present.) (Krol et al.;2010). (NP\_173217 and NP\_177451 exhibit 70% AA identity.)

NP\_199705;AT5G48940 Leucine rich repeat transmembrane protein kinase

NP\_200415;AT5G56040; Leucine rich repeat transmembrane protein kinase

**2.2 The members below possess a TM domain at the amino terminus and a second** 

NP\_201029;AT5G62230; Erecta – like 1 (ERL1); kinase. Mediates morphological alterations.

NP\_173217;AT1G17750;Leucine rich repeat / transmembrane protein kinase. PEP receptor 2

NP\_177451; AT1G73080; ATP binding / protein serine/ threonine kinase, PEP1 receptor (PEPR1). (PEP1and 2 are implicated in Arabidopsis development and immunity) ( Postel , et al.;2010). (PEPR1 and PEPR2, both perceive the existence of an endogenous danger signal Peptide 1 when such a peptide is present.) (Krol et al.;2010). (NP\_173217 and NP\_177451

NP\_199705;AT5G48940 Leucine rich repeat transmembrane protein kinase

NP\_189066;AT3G24240; Leucine rich repeat transmembrane protein kinase

NP\_200415;AT5G56040; Leucine rich repeat transmembrane protein kinase

**one in front of the STYKc domain:** 

NP\_196335;AT5G07180; Erecta – like 2 (ERL 2); kinase

(PEPR2). The amino terminal TM islost (overly mutated).

(Uchida et al.;2011).

exhibit 70% AA identity.)

NP\_201198; AT5G63930; Leucine rich repeat transmembrane protein kinase

NP\_174809:AT1G35710; Leucine rich repeat transmembrane protein kinase

NP\_192625, AT4G08850; Leucine rich repeat transmembrane protein kinase

NP\_200956;AT5G61480; Leucine rich repeat transmembrane protein kinase..PXY receptor. (This receptor like-kinase is essential for polarity during plant vascular tissue development. (Fisher &Turner,2007)

NP\_176483;AT1G62950; Leucine rich repeat transmembrane protein kinase

NP\_565084;AT1G74360; Leucine rich repeat transmembrane protein kinase

NP\_177374;AT1G72300; Leucine rich repeat transmembrane protein kinase, (This protein "perceives "phytosulfokines (Amano et al., 2007)).

NP\_190742;AT3G51740; Inflorescence Meristem Receptor-Like Kinase (IMK2)

The LRR and TM Containing Multi-Domain Proteins in Arabidopsis 91

NP\_565489;AT2G20850; (SRF1) Strubbelig receptor family 1; kinase. All LRR domains are

NP\_192248;AT4G03390; (SRF3) Strubbelig receptor family 3; kinase. The amino terminal TM

NP\_193944;AT4G22130; (SRF8) Strubbelig receptor family 8, kinase. All LRR domains are

Note: For molecules such as NP\_177363 SMART does not recognize any LRR regions. Hence, these

**3. Proteins that contain an S\_TKc domain: (AA homology is 44% for S\_TKc** 

NP\_173166;AT1G17230; Leucine rich repeat / transmembrane protein kinase

NP\_174673;AT1G34110; Leucine rich repeat / transmembrane protein kinase

NP\_567748;AT4G26540; Leucine rich repeat / transmembrane protein kinase

NP\_195341;AT4G36180; Leucine rich repeat / transmembrane protein kinase

Not shown:

lost. (SMART).

lost.(SMART).

**vs. STYKc.)** 

molecules are not listed here.

is duplicated. All LRR domains are lost. (SMART).

NP\_201529;AT5G67280; Receptor-Like Kinase (RLK)

The Strubbelig Receptor Family Kinases:

NP\_196300;AT5G06820; (SRF2) Strubbelig receptor family 2; kinase. An amino terminal TM is lost. SRFs affect the formation and shape of several organs by influencing cell morphogenesis, the orientation of the division plane and cell proliferation. (Chevalier et al., 2005).

NP\_566444;AT3G13065; (SRF4) Strubbelig receptor family 4; kinase

NP\_178019;AT1G78980; (SRF5) Strubbelig receptor family 5, kinase . The amino terminal TM is lost.

NP\_175777;AT1G53730; (SRF6) Strubbelig receptor family 6; kinase

NP\_188052;AT3G14350; (SRF7) Strubbelig receptor family 7; kinase.. The amino terminal TM is lost.

Not shown:

;

90 Gene Duplication

NP\_196300;AT5G06820; (SRF2) Strubbelig receptor family 2; kinase. An amino terminal TM

morphogenesis, the orientation of the division plane and cell proliferation. (Chevalier et al.,

NP\_178019;AT1G78980; (SRF5) Strubbelig receptor family 5, kinase . The amino terminal

NP\_188052;AT3G14350; (SRF7) Strubbelig receptor family 7; kinase.. The amino terminal

is lost. SRFs affect the formation and shape of several organs by influencing cell

NP\_566444;AT3G13065; (SRF4) Strubbelig receptor family 4; kinase

NP\_175777;AT1G53730; (SRF6) Strubbelig receptor family 6; kinase

NP\_201529;AT5G67280; Receptor-Like Kinase (RLK)

The Strubbelig Receptor Family Kinases:

2005).

TM is lost.

TM is lost.

NP\_565489;AT2G20850; (SRF1) Strubbelig receptor family 1; kinase. All LRR domains are lost. (SMART).

NP\_192248;AT4G03390; (SRF3) Strubbelig receptor family 3; kinase. The amino terminal TM is duplicated. All LRR domains are lost. (SMART).

NP\_193944;AT4G22130; (SRF8) Strubbelig receptor family 8, kinase. All LRR domains are lost.(SMART).

Note: For molecules such as NP\_177363 SMART does not recognize any LRR regions. Hence, these molecules are not listed here.
