The structure and function of several important types of protein molecules mediated by single trans-membrane conductor signal transductivity.

< td align "middle" > phosphate group of the subject protein serine/suline kinase serine/suline hydroxy protein tyrosine kinase tyrosine phenolic hydroxyproteome/lysine/arginine kinase, ε-amino . protein cysteine kinase -based protein winterline/glutamate kinase glutinine

the first two types of kinases are currently more understood, many have obtained cDNA cloning, but the understanding of the longer two is still very limited.

of protein wire/suline kinase and protein tyrosine kinase can be found in Table 21-5.

table 21-5 protein kinase classification

. < > Calcium / calmodulindependent protein kinase I.

1. proteosine/suline kinase

(1) Cyclic nucleotcleide

PKA α cAMPdependent protein kinase catalytic, α form

B. PKA beta cAMPdependent protein kinase catalytic, β form

C. PKA cAMPdependent protein kinase catalytic, γ form

D. cGPK alpha c" >GMPdependent protein kinase α form

. cGPK beta cGMPdependent protein kinase β form

(2) Diacylglycerol adjusteded: sbh.

PKC α protein kinase C α

PKC β protein. Kinase C β

PKC γ protein kinase C γ

PKC δ protein kinase C δ

PKC ε protein kinase C ε

PKC ζ protein kinase C ζ

PKC η protein kinase C η

(3) Calcium/calmodulin

. CaMII.α Calcium/calmodulindependent protein kinase II.α. camii.β Calcium/calmodulindependent protein kinase II.βCaMII.γ Calcium/calmodulindependent protein kinase II.γCaMIII.Calcium/calmodulindependent protein kinase III.CaMIV.Calcium/calmodulindependent protein kinase IV.PSKHI Putative." proteinserine kinase (4) Ribosomal S6 protein kinaseS6kI., S6KII., 70kDaS6 (5) Serpentine receptor kinase (1) β ARK beta Adrenergic receptor protein kinase(2) β ARKelate protein kinase (3) Rhodopsin kinase (6) Casein kinase II.. (7) Glycogen synthase kinase 3 (8) cdc 2 family (9) cdc 2 related protein kinase (10) MAP kinase (mitogend protein kinasesEPK-1, ERK-2, ERK-3, ERK-5 (extracellular signal-regulatory kinaseJNK (c-Jun N-terminal kinase), P38, etc.. (11) MOS/Raf protein kinase2. Protein tyrosine kinase (1) Growth factor receptorsEGFR: EGFR.erbB2, erbB3INSR:INSR, IGF1RFGFR: FGFR, FGFR2, ckitDGFR: PDGFR, CSFIR(2) Nonreceptor tyrosine kinase. src family: src, Yes, Lyn, Fyn, Lck, etc. Syk family: Syk, ZAP70JAK family: JAK1, JAK2, JAK3Tec family: A variety of protein kinases listed in the table Btk, Itk, etc

are important signal transducting molecules, which cannot be described here. Among these protein kinases, PKA, PKG, PKC, MAPK and PPK have a greater impact on cellular function. PKA, PKG, and PKC are already mentioned in the G protein coupled complex, so mapK and PPK are only described here.

(1) MAP Kinase (Mitogen Activated Protein Kinase, MAPK)

MAPK belongs to the protein wire/suline kinase and is a class of important molecules that accept the signals converted and transmitted by membrane recipients and bring them into the nucleus of the cell, all of which play a key role in a variety of recipient signal transmission pathways. In unstilled cells, MAPK is stationary, and when it receives the phosphatation regulatory signal of the upstream molecule MAPKK (MAp Kinase Kinase), the adjacent suline and tyrosine in mapK are phosphatized, thus becoming the active form of MAPK.

MAPK step-by-step activation system consisting of protein kinases. The MAPKK, which makes MAPK phosphate, is regulated by MAPKKK (MAp Kinase Kinase Kinase). This step-by-step activation system is then regulated by its upstream molecules.

mapK is activated, it is transferred to the nuclei of the cell. In the nuclei, it can cause some transcription factors to phosphate, thus changing the state of gene expression in the cell. In addition, it can make some other enzymes phosphate to change their activity. MapK is known to play a key role in the regulation of a variety of cellular functions, especially in the process of cell proliferation, differentiation and apoptosis.

mapK pathway has been found in fruit flies in 7 species, in mammalian cells have been confirmed at least three MAPK members, namely ERK, JNK and P38. Their regulatory mechanism and action of the target molecules are different.

(2) Protein Tyrosine Kinase (PTK)

Protein Tyrosine Kinase actes on tyrosine residues inprotein to phosphate it, and the earliest thing that many cell signal transduces is tyrosine phosphate of multiple proteins.

In the process of cell growth and differentiation, tyrosine phosphate has mostly positive regulatory effects, whether it is > growth factor after the role of normal cell proliferation, malignant tumor cell proliferation, or T cells, B cells or hypertrophic cells are accompanied by the instantaneous active tyrosine phosphate of a variety of protein molecules. Inhibitors of the protein tyrosine kinase can block the response of the above cells.

According to the position of the protein tyrosine kinase in the cell, it can be divided into three categories:

A. protein tyrosine kinase

this kind of protein tyrosine kinase is a trans-membrane protein, its cell outside is divided into licturic binding region, the middle cross-membrane region, the intracellular part contains the protein tyrosine kinase catalytic domain (Figure 21-17).

protein tyrosine kinase digestor and ligation often form a binary polymer, followed by an increase in enzyme activity, so that the tyrosine phosphatization of the intracellulation of the subject, phosphatization of the subject enzyme activity further enhanced. More importantly, phosphatized subjects can collect signal molecules containing the SH2 domain (see later) to transmit signals to downstream molecules.

B. The protein tyrosine located in the cell pulp part.