Whole Cells - Molecular Theory of the Living Cell - page 463

Type (Generic Names)

Growth Factors
Hormones
Stress

Heat Shock
Arsenite, Il-1
LPS

1

Stimuli

Progestrone
(Xenopus)

PMA

2

Receptor

RAS

3

PKC

(MAP4K)

4

MAP3K

Ra-1 MOS ??

MEKK Raf-1

5

MAPKK

?? MEK1/2 RKK

6

ERK 1/2 MAPK

RK(HOG ?)

JNK

RSK

7 MAPKAPK2 MAPKAPK

8

Cell death, growth, proliferation, differentiation, oncogenesis, cell cycle
regulation, etc.

Responses*

A B C D * Kinematic and

dynamic responses
(see Section 2.3.5)

Tokens (Specific Names)

Fig. 12.36 The MAPK Signal Transduction Pathways (Cascades), adopted from Seger and Krebs
(1995). Three distinct signal transduction pathways are shown. All of these pathways are com-
posed of six functional elements (numbered 2-7), which, when activated by primary messengers
or stimuli (numbered 1), lead to specific functions or responses (numbered 8). The kinematics
(concerned with the question as to which of the possible pathways are actually activated under a
given environmental condition) and the dynamics (concerned with the question about for how long
and how fast a given pathway is activated) are determined by the primary messenger (or primary
perturbation) and the state of the cell involved. To completely describe a signal transduction event,
it is necessary to elucidate not only the kinematics but also dynamics of signal transduction since
these are the complementary aspects of signal transduction (Sect. 2.3.5 ). MAPK mitogen-activated
protein kinase, MAPKK or MAP2K MAPK kinase, MAPKKK or MAP3K MAPKK kinase, MAP4K
MAP3K kinase, RAS rat sarcoma, PKC protein kinase C, MEKK MEK kinase, MEK mitogen-
activated, ERK-activating kinase, MEK ½ MEK 1 and 2, ERK ½ ERK 1 and 2, ERK extracellular
regulated kinase, RSK ribosomal S6 protein kinase, MAPKAPK2 , MAP kinase-activated protein
kinase 2. This table exemplifies the distinction between types and tokens discussed in Sect. 6.3.9.
Seger and Krebs refer to types and tokens as generic and specific names, respectively

It is a truism to state that no communication is possible without a language .
Since communication is essential for cells to survive and function, cells must
possess languages of their own, and such a hypothetical language was referred to
as the cell language in (Ji 1997a, b) (see Sect. 6.1.2 ) . Just as the computer language